blob: 8ad4129fe4d1b859964f26affca3f451fa008985 [file] [log] [blame]
Tim Petersaf8446f2001-12-21 21:36:50 +00001What's New in Python 2.3 alpha 1?
2XXX Release date: DD-MMM-2002 XXX
3=================================
4
5Type/class unification and new-style classes
6
7Core and builtins
8
Marc-André Lemburge92e0a92002-02-09 11:28:43 +00009- The UTF-8 codec will now encode and decode Unicode surrogates
10 correctly and without raising exceptions for unpaired ones.
11
Neal Norwitz649b7592002-01-01 19:07:13 +000012- file.xreadlines() now raises a ValueError if the file is closed:
13 Previously, an xreadlines object was returned which would raise
14 a ValueError when the xreadlines.next() method was called.
15
Tim Petersaf8446f2001-12-21 21:36:50 +000016Extension modules
17
Neal Norwitze790eae2002-01-01 21:14:12 +000018- dl now builds on every system that has dlfcn.h. Failure in case
Martin v. Löwis93227272002-01-01 20:18:30 +000019 of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
20 is called.
21
Tim Petersaf8446f2001-12-21 21:36:50 +000022Library
23
Guido van Rossum606fe4e2001-12-28 20:57:14 +000024- ftplib: to safeguard the user's privacy, anonymous login will use
25 "anonymous@" as default password, rather than the real user and host
26 name.
27
Fred Drake36736122002-01-10 13:50:31 +000028- webbrowser: tightened up the command passed to os.system() so that
29 arbitrary shell code can't be executed because a bogus URL was
30 passed in.
31
Tim Peters11bd9942002-02-01 00:52:29 +000032- gettext.translation has an optional fallback argument, and
Martin v. Löwisa55ffae2002-01-11 06:58:49 +000033 gettext.find an optional all argument. Translations will now fallback
34 on a per-message basis.
Martin v. Löwis1be64192002-01-11 06:33:28 +000035
Martin v. Löwis9668b932002-01-12 11:27:42 +000036- distutils bdist commands now offer a --skip-build option.
37
Tim Petersaf8446f2001-12-21 21:36:50 +000038Tools/Demos
39
40Build
41
42C API
43
Marc-André Lemburg3e3eacb2002-01-09 16:21:27 +000044- The "u#" parser marker will now pass through Unicode object as-is
45 without going through the buffer API.
46
Martin v. Löwis7198a522002-01-01 19:59:11 +000047- The enumerators of cmp_op have been renamed to use the prefix PyCmp_.
48
Tim Peters10a3bb52001-12-25 19:07:38 +000049- An old #define of ANY as void has been removed from pyport.h. This
50 hasn't been used since Python's pre-ANSI days, and the #define has
51 been marked as obsolete since then. SF bug 495548 says it created
52 conflicts with other packages, so keeping it around wasn't harmless.
53
Tim Petersaf8446f2001-12-21 21:36:50 +000054- Because Python's magic number scheme broke on January 1st, we decided
55 to stop Python development. Thanks for all the fish!
56
Marc-André Lemburge92e0a92002-02-09 11:28:43 +000057- Some of us don't like fish, so we changed Python's magic number
58 scheme to a new one. See Python/import.c for details.
59
Tim Petersaf8446f2001-12-21 21:36:50 +000060New platforms
61
Martin v. Löwisa6e97582002-01-01 18:41:33 +000062- GNU/Hurd is now supported.
63
Tim Petersaf8446f2001-12-21 21:36:50 +000064Tests
65
66Windows
67
Tim Petersab034fa2002-02-01 11:27:43 +000068- os.waitpid() is now implemented for Windows, and can be used to block
69 until a specified process exits. This is similar to, but not exactly
70 the same as, os.waitpid() on POSIX systems. If you're waiting for
71 a specific process whose pid was obtained from one of the spawn()
72 functions, the same Python os.waitpid() code works across platforms.
73 See the docs for details.
74
Tim Peters11bd9942002-02-01 00:52:29 +000075- New tempfile.TemporaryFile implementation for Windows: this doesn't
76 need a TemproraryFileWrapper wrapper anymore, and should be immune
77 to a nasty problem: before 2.3, if you got a temp file on Windows, it
78 got wrapped in an object whose close() method first closed the
79 underlying file, then deleted the file. This usually worked fine.
80 However, the spawn family of functions on Windows create (at a low C
81 level) the same set of open files in the spawned process Q as were
82 open in the spawning process P. If a temp file f was among them, then
83 doing f.close() in P first closed P's C-level file handle on f, but Q's
84 C-level file handle on f remained open, so the attempt in P to delete f
85 blew up with a "Permission denied" error (Windows doesn't allow
86 deleting open files). This was surprising, subtle, and difficult to
87 work around.
88
89- The os module now exports all the symbolic constants usable with the
90 low-level os.open() on Windows: the new constants in 2.3 are
91 O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
92 The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
93 O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
94 to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
95 (so specify both if you want both; note that neither is useful unless
96 specified with O_CREAT too).
97
Tim Petersaf8446f2001-12-21 21:36:50 +000098Mac
99
100
Tim Peters909c0912001-12-14 23:16:18 +0000101What's New in Python 2.2 final?
102Release date: 21-Dec-2001
103===============================
104
105Type/class unification and new-style classes
106
Barry Warsaw52acb492001-12-21 20:04:22 +0000107- pickle.py, cPickle: allow pickling instances of new-style classes
108 with a custom metaclass.
109
Tim Peters909c0912001-12-14 23:16:18 +0000110Core and builtins
111
Barry Warsaw52acb492001-12-21 20:04:22 +0000112- weakref proxy object: when comparing, unwrap both arguments if both
113 are proxies.
114
Tim Peters909c0912001-12-14 23:16:18 +0000115Extension modules
116
Barry Warsaw52acb492001-12-21 20:04:22 +0000117- binascii.b2a_base64(): fix a potential buffer overrun when encoding
118 very short strings.
119
120- cPickle: the obscure "fast" mode was suspected of causing stack
121 overflows on the Mac. Hopefully fixed this by setting the recursion
122 limit much smaller. If the limit is too low (it only affects
123 performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
124 when compiling cPickle.c (or in pyconfig.h).
125
Tim Peters909c0912001-12-14 23:16:18 +0000126Library
127
Barry Warsaw52acb492001-12-21 20:04:22 +0000128- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
129 close or delete time).
130
131- rfc822.py: fixed a bug where the address '<>' was converted to None
132 instead of an empty string (also fixes the email.Utils module).
133
134- xmlrpclib.py: version 1.0.0; uses precision for doubles.
135
136- test suite: the pickle and cPickle tests were not executing any code
137 when run from the standard regresssion test.
138
Tim Peters909c0912001-12-14 23:16:18 +0000139Tools/Demos
140
141Build
142
143C API
144
145New platforms
146
147Tests
148
149Windows
150
Barry Warsaw52acb492001-12-21 20:04:22 +0000151- distutils package: fixed broken Windows installers (bdist_wininst).
152
153- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
154 instances are deleted at process exit time.
155
156- socket.py: prevent mysterious warnings when socket instances are
157 deleted at process exit time.
158
159- posixmodule.c: fix a Windows crash with stat() of a filename ending
160 in backslash.
161
Tim Peters909c0912001-12-14 23:16:18 +0000162Mac
163
Barry Warsaw52acb492001-12-21 20:04:22 +0000164- The Carbon toolbox modules have been upgraded to Universal Headers
165 3.4, and experimental CoreGraphics and CarbonEvents modules have
166 been added. All only for framework-enabled MacOSX.
167
Tim Peters909c0912001-12-14 23:16:18 +0000168
Tim Peters6272dfd2001-12-13 19:34:00 +0000169What's New in Python 2.2c1?
170Release date: 14-Dec-2001
Tim Petersb3c9af12001-11-17 00:21:57 +0000171===========================
172
173Type/class unification and new-style classes
174
Barry Warsaw06557452001-12-14 20:47:12 +0000175- Guido's tutorial introduction to the new type/class features has
176 been extensively updated. See
177
178 http://www.python.org/2.2/descrintro.html
179
180 That remains the primary documentation in this area.
181
Guido van Rossum33bab012001-12-05 22:45:48 +0000182- Fixed a leak: instance variables declared with __slots__ were never
183 deleted!
184
Guido van Rossum4b800852001-12-03 00:54:52 +0000185- The "delete attribute" method of descriptor objects is called
186 __delete__, not __del__. In previous releases, it was mistakenly
187 called __del__, which created an unfortunate overloading condition
188 with finalizers. (The "get attribute" and "set attribute" methods
189 are still called __get__ and __set__, respectively.)
190
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000191- Some subtle issues with the super built-in were fixed:
192
193 (a) When super itself is subclassed, its __get__ method would still
194 return an instance of the base class (i.e., of super).
195
196 (b) super(C, C()).__class__ would return C rather than super. This
197 is confusing. To fix this, I decided to change the semantics of
198 super so that it only applies to code attributes, not to data
199 attributes. After all, overriding data attributes is not
200 supported anyway.
201
202 (c) The __get__ method didn't check whether the argument was an
203 instance of the type used in creation of the super instance.
204
Guido van Rossumcd7b7d62001-12-04 21:02:07 +0000205- Previously, hash() of an instance of a subclass of a mutable type
206 (list or dictionary) would return some value, rather than raising
207 TypeError. This has been fixed. Also, directly calling
208 dict.__hash__ and list.__hash__ now raises the same TypeError
209 (previously, these were the same as object.__hash__).
Guido van Rossumcdbbd0a2001-12-03 15:46:59 +0000210
Guido van Rossumd331cb52001-12-05 19:46:42 +0000211- New-style objects now support deleting their __dict__. This is for
212 all intents and purposes equivalent to assigning a brand new empty
213 dictionary, but saves space if the object is not used further.
214
Tim Petersb3c9af12001-11-17 00:21:57 +0000215Core and builtins
216
Tim Peters3caca232001-12-06 06:23:26 +0000217- -Qnew now works as documented in PEP 238: when -Qnew is passed on
218 the command line, all occurrences of "/" use true division instead
219 of classic division. See the PEP for details. Note that "all"
220 means all instances in library and 3rd-party modules, as well as in
221 your own code. As the PEP says, -Qnew is intended for use only in
222 educational environments with control over the libraries in use.
Tim Petersbf72fe22001-12-11 21:43:14 +0000223 Note that test_coercion.py in the standard Python test suite fails
224 under -Qnew; this is expected, and won't be repaired until true
225 division becomes the default (in the meantime, test_coercion is
226 testing the current rules).
Tim Peters3caca232001-12-06 06:23:26 +0000227
Fred Drake6c01e252001-12-14 17:08:12 +0000228- complex() now only allows the first argument to be a string
229 argument, and raises TypeError if either the second arg is a string
230 or if the second arg is specified when the first is a string.
231
Tim Petersb3c9af12001-11-17 00:21:57 +0000232Extension modules
233
Martin v. Löwis560da622001-11-24 09:24:51 +0000234- gc.get_referents was renamed to gc.get_referrers.
235
Tim Petersb3c9af12001-11-17 00:21:57 +0000236Library
237
Tim Peters25059d32001-12-07 20:35:43 +0000238- Functions in the os.spawn() family now release the global interpreter
239 lock around calling the platform spawn. They should always have done
240 this, but did not before 2.2c1. Multithreaded programs calling
241 an os.spawn function with P_WAIT will no longer block all Python threads
242 until the spawned program completes. It's possible that some programs
243 relies on blocking, although more likely by accident than by design.
244
Martin v. Löwis3a89b2b2001-11-25 14:35:58 +0000245- webbrowser defaults to netscape.exe on OS/2 now.
246
Martin v. Löwis652e1912001-11-25 14:50:56 +0000247- Tix.ResizeHandle exposes detach_widget, hide, and show.
248
Martin v. Löwis714d2e22001-12-02 12:26:03 +0000249- The charset alias windows_1252 has been added.
250
Barry Warsaw06557452001-12-14 20:47:12 +0000251- types.StringTypes is a tuple containing the defined string types;
252 usually this will be (str, unicode), but if Python was compiled
253 without Unicode support it will be just (str,).
254
255- The pulldom and minidom modules were synchronized to PyXML.
256
Tim Petersb3c9af12001-11-17 00:21:57 +0000257Tools/Demos
258
Barry Warsaw06557452001-12-14 20:47:12 +0000259- A new script called Tools/scripts/google.py was added, which fires
260 off a search on Google.
261
Tim Petersb3c9af12001-11-17 00:21:57 +0000262Build
263
Barry Warsaw06557452001-12-14 20:47:12 +0000264- Note that release builds of Python should arrange to define the
265 preprocessor symbol NDEBUG on the command line (or equivalent).
266 In the 2.2 pre-release series we tried to define this by magic in
267 Python.h instead, but it proved to cause problems for extension
268 authors. The Unix, Windows and Mac builds now all define NDEBUG in
269 release builds via cmdline (or equivalent) instead. Ports to
270 other platforms should do likewise.
271
Jack Jansen1999ef42001-12-06 21:47:20 +0000272- It is no longer necessary to use --with-suffix when building on a
273 case-insensitive file system (such as Mac OS X HFS+). In the build
274 directory an extension is used, but not in the installed python.
275
Tim Petersb3c9af12001-11-17 00:21:57 +0000276C API
277
Tim Petersf582b822001-12-11 18:51:08 +0000278- New function PyDict_MergeFromSeq2() exposes the builtin dict
279 constructor's logic for updating a dictionary from an iterable object
280 producing key-value pairs.
281
Tim Peterscffed4b2001-11-29 03:26:37 +0000282- PyArg_ParseTupleAndKeywords() requires that the number of entries in
Tim Petersf582b822001-12-11 18:51:08 +0000283 the keyword list equal the number of argument specifiers. This
Tim Peterscffed4b2001-11-29 03:26:37 +0000284 wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
285 dump core in some bad cases. This has been repaired. As a result,
286 PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
287 previously went unchallenged.
288
Tim Petersb3c9af12001-11-17 00:21:57 +0000289New platforms
290
291Tests
292
293Windows
294
295Mac
296
Jack Jansenffa260f2001-12-06 21:14:00 +0000297- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
298 without any trailing digits.
Tim Petersb3c9af12001-11-17 00:21:57 +0000299
Barry Warsaw06557452001-12-14 20:47:12 +0000300- Changed logic for finding python home in Mac OS X framework Pythons.
301 Now sys.executable points to the executable again, in stead of to
302 the shared library. The latter is used only for locating the python
303 home.
304
305
Tim Peters84362bc2001-10-19 17:55:30 +0000306What's New in Python 2.2b2?
Tim Peters76f7fe32001-11-15 20:02:21 +0000307Release date: 16-Nov-2001
Tim Peters84362bc2001-10-19 17:55:30 +0000308===========================
309
310Type/class unification and new-style classes
311
Guido van Rossum3d27df02001-11-15 20:27:54 +0000312- Multiple inheritance mixing new-style and classic classes in the
313 list of base classes is now allowed, so this works now:
Tim Peters76f7fe32001-11-15 20:02:21 +0000314
315 class Classic: pass
Guido van Rossum3d27df02001-11-15 20:27:54 +0000316 class Mixed(Classic, object): pass
Tim Peters76f7fe32001-11-15 20:02:21 +0000317
318 The MRO (method resolution order) for each base class is respected
319 according to its kind, but the MRO for the derived class is computed
320 using new-style MRO rules if any base clase is a new-style class.
321 This needs to be documented.
322
Tim Petersa427a2b2001-10-29 22:25:45 +0000323- The new builtin dictionary() constructor, and dictionary type, have
324 been renamed to dict. This reflects a decade of common usage.
325
Guido van Rossum3fc08d22001-11-15 20:33:10 +0000326- dict() now accepts an iterable object producing 2-sequences. For
327 example, dict(d.items()) == d for any dictionary d. The argument,
328 and the elements of the argument, can be any iterable objects.
329
Guido van Rossum7ad2d1e2001-10-29 22:11:00 +0000330- New-style classes can now have a __del__ method, which is called
331 when the instance is deleted (just like for classic classes).
332
Guido van Rossum12d955c2001-10-26 14:56:06 +0000333- Assignment to object.__dict__ is now possible, for objects that are
334 instances of new-style classes that have a __dict__ (unless the base
335 class forbids it).
336
Guido van Rossumc8e56452001-10-22 00:43:43 +0000337- Methods of built-in types now properly check for keyword arguments
338 (formerly these were silently ignored). The only built-in methods
339 that take keyword arguments are __call__, __init__ and __new__.
340
Guido van Rossum86443212001-10-27 22:28:54 +0000341- The socket function has been converted to a type; see below.
342
Tim Peters84362bc2001-10-19 17:55:30 +0000343Core and builtins
344
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000345- Assignment to __debug__ raises SyntaxError at compile-time. This
346 was promised when 2.1c1 was released as "What's New in Python 2.1c1"
Barry Warsaw012852b2001-11-16 16:17:27 +0000347 (see below) says.
Jeremy Hylton249aaed2001-11-09 21:06:24 +0000348
Guido van Rossum12d955c2001-10-26 14:56:06 +0000349- Clarified the error messages for unsupported operands to an operator
350 (like 1 + '').
351
Tim Peters84362bc2001-10-19 17:55:30 +0000352Extension modules
353
Tim Peters5ebfd362001-11-13 23:11:19 +0000354- mmap has a new keyword argument, "access", allowing a uniform way for
355 both Windows and Unix users to create read-only, write-through and
356 copy-on-write memory mappings. This was previously possible only on
357 Unix. A new keyword argument was required to support this in a
358 uniform way because the mmap() signuatures had diverged across
359 platforms. Thanks to Jay T Miller for repairing this!
360
Tim Peters169ded02001-11-03 19:57:21 +0000361- By default, the gc.garbage list now contains only those instances in
362 unreachable cycles that have __del__ methods; in 2.1 it contained all
363 instances in unreachable cycles. "Instances" here has been generalized
364 to include instances of both new-style and old-style classes.
365
Guido van Rossum12d955c2001-10-26 14:56:06 +0000366- The socket module defines a new method for socket objects,
367 sendall(). This is like send() but may make multiple calls to
Guido van Rossum86443212001-10-27 22:28:54 +0000368 send() until all data has been sent. Also, the socket function has
369 been converted to a subclassable type, like list and tuple (etc.)
370 before it; socket and SocketType are now the same thing.
Guido van Rossum12d955c2001-10-26 14:56:06 +0000371
372- Various bugfixes to the curses module. There is now a test suite
373 for the curses module (you have to run it manually).
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000374
Guido van Rossum692adf12001-10-30 03:03:03 +0000375- binascii.b2a_base64 no longer places an arbitrary restriction of 57
376 bytes on its input.
377
Tim Peters84362bc2001-10-19 17:55:30 +0000378Library
379
Tim Peters5ebfd362001-11-13 23:11:19 +0000380- tkFileDialog exposes a Directory class and askdirectory
Martin v. Löwis25ee87c2001-11-07 22:38:08 +0000381 convenience function.
382
Tim Peters75335872001-11-03 19:35:43 +0000383- Symbolic group names in regular expressions must be unique. For
384 example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
385 single name can't mean both "group 1" and "group 2" simultaneously.
Barry Warsaw012852b2001-11-16 16:17:27 +0000386 Python 2.2 detects this error at regexp compilation time;
387 previously, the error went undetected, and results were
388 unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
389 pattern.subn() methods have been rewritten in C. Also, an
390 experimental function/method finditer() has been added, which works
391 like findall() but returns an iterator.
Tim Peters75335872001-11-03 19:35:43 +0000392
Martin v. Löwisb7b32602001-11-02 23:48:20 +0000393- Tix exposes more commands through the classes DirSelectBox,
394 DirSelectDialog, ListNoteBook, Meter, CheckList, and the
395 methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
396 tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
397
Tim Peters98791af2001-10-23 01:59:54 +0000398- Traceback objects are now scanned by cyclic garbage collection, so
399 cycles created by casual use of sys.exc_info() no longer cause
400 permanent memory leaks (provided garbage collection is enabled).
401
Guido van Rossum49192142001-10-24 20:51:44 +0000402- os.extsep -- a new variable needed by the RISCOS support. It is the
403 separator used by extensions, and is '.' on all platforms except
404 RISCOS, where it is '/'. There is no need to use this variable
405 unless you have a masochistic desire to port your code to RISCOS.
406
Barry Warsaw012852b2001-11-16 16:17:27 +0000407- mimetypes.py has optional support for non-standard, but commonly
408 found types. guess_type() and guess_extension() now accept an
409 optional `strict' flag, defaulting to true, which controls whether
410 recognize non-standard types or not. A few non-standard types we
411 know about have been added. Also, when run as a script, there are
412 new -l and -e options.
413
414- statcache is now deprecated.
415
416- email.Utils.formatdate() now produces the preferred RFC 2822 style
417 dates with numeric timezones (it used to produce obsolete dates
418 hard coded to "GMT" timezone). An optional `localtime' flag is
419 added to produce dates in the local timezone, with daylight savings
420 time properly taken into account.
421
422- In pickle and cPickle, instead of masking errors in load() by
423 transforming them into SystemError, we let the original exception
424 propagate out. Also, implement support for __safe_for_unpickling__
425 in pickle, as it already was supported in cPickle.
426
Tim Peters84362bc2001-10-19 17:55:30 +0000427Tools/Demos
428
429Build
430
Barry Warsaw012852b2001-11-16 16:17:27 +0000431- The dbm module is built using libdb1 if available. The bsddb module
432 is built with libdb3 if available.
433
434- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
435
Tim Peters84362bc2001-10-19 17:55:30 +0000436C API
437
Tim Peters1fc240e2001-10-26 05:06:50 +0000438- New function PySequence_Fast_GET_SIZE() returns the size of a non-
439 NULL result from PySequence_Fast(), more quickly than calling
440 PySequence_Size().
441
Barry Warsaw012852b2001-11-16 16:17:27 +0000442- New argument unpacking function PyArg_UnpackTuple() added.
443
444- New functions PyObject_CallFunctionObjArgs() and
445 PyObject_CallMethodObjArgs() have been added to make it more
446 convenient and efficient to call functions and methods from C.
447
448- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
449 possible that this will propagate errors it didn't before.
450
451- New function PyObject_CheckReadBuffer(), which returns true if its
452 argument supports the single-segment readable buffer interface.
453
Tim Peters84362bc2001-10-19 17:55:30 +0000454New platforms
455
Guido van Rossum86443212001-10-27 22:28:54 +0000456- We've finally confirmed that this release builds on HP-UX 11.00,
457 *with* threads, and passes the test suite.
458
Tim Peters7a33d8b2001-11-05 02:51:07 +0000459- Thanks to a series of patches from Michael Muller, Python may build
460 again under OS/2 Visual Age C++.
461
Guido van Rossum49192142001-10-24 20:51:44 +0000462- Updated RISCOS port by Dietmar Schwertberger.
463
Tim Peters84362bc2001-10-19 17:55:30 +0000464Tests
465
Andrew M. Kuchling15e03532001-10-22 16:37:10 +0000466- Added a test script for the curses module. It isn't run automatically;
467 regrtest.py must be run with '-u curses' to enable it.
468
Tim Peters84362bc2001-10-19 17:55:30 +0000469Windows
470
Barry Warsaw012852b2001-11-16 16:17:27 +0000471Mac
472
473- PythonScript has been moved to unsupported and is slated to be
474 removed completely in the next release.
475
476- It should now be possible to build applets that work on both OS9 and
477 OSX.
478
479- The core is now linked with CoreServices not Carbon; as a side
480 result, default 8bit encoding on OSX is now ASCII.
481
482- Python should now build on OSX 10.1.1
483
Tim Peters84362bc2001-10-19 17:55:30 +0000484
Tim Petersabf925f2001-09-28 21:53:42 +0000485What's New in Python 2.2b1?
Guido van Rossum1c486092001-10-19 02:05:35 +0000486Release date: 19-Oct-2001
Tim Petersabf925f2001-09-28 21:53:42 +0000487===========================
488
489Type/class unification and new-style classes
490
Guido van Rossum687ae002001-10-15 22:03:32 +0000491- New-style classes are now always dynamic (except for built-in and
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000492 extension types). There is no longer a performance penalty, and I
Guido van Rossum687ae002001-10-15 22:03:32 +0000493 no longer see another reason to keep this baggage around. One relic
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000494 remains: the __dict__ of a new-style class is a read-only proxy; you
495 must set the class's attribute to modify it. As a consequence, the
Guido van Rossum687ae002001-10-15 22:03:32 +0000496 __defined__ attribute of new-style types no longer exists, for lack
497 of need: there is once again only one __dict__ (although in the
Guido van Rossum3eea25c2001-10-16 00:46:57 +0000498 future a __cache__ may be resurrected with a similar function, if I
499 can prove that it actually speeds things up).
Guido van Rossum50fda3b2001-10-04 19:46:06 +0000500
Tim Peters1c9ca872001-10-04 06:43:12 +0000501- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
502 always returned None, even when there was a class docstring).
503
504- doctest now finds and runs docstrings attached to new-style classes,
505 class methods, static methods, and properties.
506
Guido van Rossum9074ef62001-10-16 21:34:49 +0000507Core and builtins
Tim Petersabf925f2001-09-28 21:53:42 +0000508
Guido van Rossuma8bcf802001-10-15 15:53:58 +0000509- A very subtle syntactical pitfall in list comprehensions was fixed.
510 For example: [a+b for a in 'abc', for b in 'def']. The comma in
511 this example is a mistake. Previously, this would silently let 'a'
512 iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
513 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
514 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
515 Note that [a for a in <singleton>] is a convoluted way to say
516 [<singleton>] anyway, so it's not like any expressiveness is lost.
517
Guido van Rossum9074ef62001-10-16 21:34:49 +0000518- getattr(obj, name, default) now only catches AttributeError, as
519 documented, rather than returning the default value for all
520 exceptions (which could mask bugs in a __getattr__ hook, for
521 example).
522
Fred Drakecb7a6b52001-10-22 18:41:51 +0000523- Weak reference objects are now part of the core and offer a C API.
Fred Drake934d2a42001-10-18 18:18:06 +0000524 A bug which could allow a core dump when binary operations involved
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000525 proxy reference has been fixed. weakref.ReferenceError is now a
Barry Warsawf6fb1712001-10-19 05:35:40 +0000526 built-in exception.
Fred Drake934d2a42001-10-18 18:18:06 +0000527
Guido van Rossum1c486092001-10-19 02:05:35 +0000528- unicode(obj) now behaves more like str(obj), accepting arbitrary
529 objects, and calling a __unicode__ method if it exists.
530 unicode(obj, encoding) and unicode(obj, encoding, errors) still
Marc-André Lemburgb5507ec2001-10-19 12:02:29 +0000531 require an 8-bit string or character buffer argument.
Guido van Rossum1c486092001-10-19 02:05:35 +0000532
Barry Warsawf6fb1712001-10-19 05:35:40 +0000533- isinstance() now allows any object as the first argument and a
534 class, a type or something with a __bases__ tuple attribute for the
535 second argument. The second argument may also be a tuple of a
536 class, type, or something with __bases__, in which case isinstance()
537 will return true if the first argument is an instance of any of the
538 things contained in the second argument tuple. E.g.
539
540 isinstance(x, (A, B))
541
542 returns true if x is an instance of A or B.
543
Guido van Rossum9074ef62001-10-16 21:34:49 +0000544Extension modules
545
546- thread.start_new_thread() now returns the thread ID (previously None).
547
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000548- binascii has now two quopri support functions, a2b_qp and b2a_qp.
549
Guido van Rossumc524d952001-10-19 01:31:59 +0000550- readline now supports setting the startup_hook and the
551 pre_event_hook, and adds the add_history() function.
Martin v. Löwis0daad592001-09-30 21:09:59 +0000552
Guido van Rossumc524d952001-10-19 01:31:59 +0000553- os and posix supports chroot(), setgroups() and unsetenv() where
554 available. The stat(), fstat(), statvfs() and fstatvfs() functions
555 now return "pseudo-sequences" -- the various fields can now be
556 accessed as attributes (e.g. os.stat("/").st_mtime) but for
557 backwards compatibility they also behave as a fixed-length sequence.
558 Some platform-specific fields (e.g. st_rdev) are only accessible as
Guido van Rossum98bf58f2001-10-18 20:34:25 +0000559 attributes.
560
561- time: localtime(), gmtime() and strptime() now return a
562 pseudo-sequence similar to the os.stat() return value, with
563 attributes like tm_year etc.
Martin v. Löwis16628c92001-10-04 22:46:41 +0000564
Guido van Rossum9074ef62001-10-16 21:34:49 +0000565- Decompression objects in the zlib module now accept an optional
566 second parameter to decompress() that specifies the maximum amount
567 of memory to use for the uncompressed data.
Tim Petersabf925f2001-09-28 21:53:42 +0000568
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000569- optional SSL support in the socket module now exports OpenSSL
570 functions RAND_add(), RAND_egd(), and RAND_status(). These calls
571 are useful on platforms like Solaris where OpenSSL does not
Barry Warsawf6fb1712001-10-19 05:35:40 +0000572 automatically seed its PRNG. Also, the keyfile and certfile
573 arguments to socket.ssl() are now optional.
574
575- posixmodule (and by extension, the os module on POSIX platforms) now
576 exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Jeremy Hyltoncb441432001-10-19 03:40:19 +0000577
Guido van Rossum9074ef62001-10-16 21:34:49 +0000578Library
Guido van Rossum3c288632001-10-16 21:13:49 +0000579
Tim Peters7402f792001-10-02 03:53:41 +0000580- doctest now excludes functions and classes not defined by the module
581 being tested, thanks to Tim Hochberg.
582
Fred Drakecb7a6b52001-10-22 18:41:51 +0000583- HotShot, a new profiler implemented using a C-based callback, has
584 been added. This substantially reduces the overhead of profiling,
585 but it is still quite preliminary. Support modules and
586 documentation will be added in upcoming releases (before 2.2 final).
587
Guido van Rossumc4b09b42001-10-04 10:19:00 +0000588- profile now produces correct output in situations where an exception
589 raised in Python is cleared by C code (e.g. hasattr()). This used
590 to cause wrong output, including spurious claims of recursive
591 functions and attribution of time spent to the wrong function.
592
Tim Peters0a1fc4e2001-10-07 03:12:08 +0000593 The code and documentation for the derived OldProfile and HotProfile
594 profiling classes was removed. The code hasn't worked for years (if
595 you tried to use them, they raised exceptions). OldProfile
596 intended to reproduce the behavior of the profiler Python used more
597 than 7 years ago, and isn't interesting anymore. HotProfile intended
598 to provide a faster profiler (but producing less information), and
599 that's a worthy goal we intend to meet via a different approach (but
600 without losing information).
601
Tim Peterscce092d2001-10-09 05:31:56 +0000602- Profile.calibrate() has a new implementation that should deliver
Tim Peters659a6032001-10-09 20:51:19 +0000603 a much better system-specific calibration constant. The constant can
604 now be specified in an instance constructor, or as a Profile class or
605 instance variable, instead of by editing profile.py's source code.
606 Calibration must still be done manually (see the docs for the profile
607 module).
608
609 Note that Profile.calibrate() must be overriden by subclasses.
610 Improving the accuracy required exploiting detailed knowledge of
611 profiler internals; the earlier method abstracted away the details
612 and measured a simplified model instead, but consequently computed
613 a constant too small by a factor of 2 on some modern machines.
Tim Peterscce092d2001-10-09 05:31:56 +0000614
Martin v. Löwis16dc7f42001-09-30 20:32:11 +0000615- quopri's encode and decode methods take an optional header parameter,
Jeremy Hylton6f543b62001-10-16 20:42:52 +0000616 which indicates whether output is intended for the header 'Q'
617 encoding.
618
Guido van Rossuma5343cc2001-10-18 18:02:07 +0000619- The SocketServer.ThreadingMixIn class now closes the request after
620 finish_request() returns. (Not when it errors out though.)
621
Barry Warsawf6fb1712001-10-19 05:35:40 +0000622- The nntplib module's NNTP.body() method has grown a `file' argument
623 to allow saving the message body to a file.
624
625- The email package has added a class email.Parser.HeaderParser which
626 only parses headers and does not recurse into the message's body.
627 Also, the module/class MIMEAudio has been added for representing
628 audio data (contributed by Anthony Baxter).
629
630- ftplib should be able to handle files > 2GB.
631
632- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
633 ON, and OFF.
634
Fred Drakecb7a6b52001-10-22 18:41:51 +0000635- xml.dom.minidom NodeList objects now support the length attribute
636 and item() method as required by the DOM specifications.
637
Guido van Rossumed554f62001-10-02 23:15:37 +0000638Tools/Demos
639
640- Demo/dns was removed. It no longer serves any purpose; a package
641 derived from it is now maintained by Anthony Baxter, see
642 http://PyDNS.SourceForge.net.
Tim Petersabf925f2001-09-28 21:53:42 +0000643
Barry Warsawf6fb1712001-10-19 05:35:40 +0000644- The freeze tool has been made more robust, and two new options have
645 been added: -X and -E.
646
Tim Petersabf925f2001-09-28 21:53:42 +0000647Build
648
Barry Warsawf6fb1712001-10-19 05:35:40 +0000649- configure will use CXX in LINKCC if CXX is used to build main() and
650 the system requires to link a C++ main using the C++ compiler.
651
Tim Petersabf925f2001-09-28 21:53:42 +0000652C API
653
Guido van Rossum6c4bce32001-10-18 19:20:25 +0000654- The documentation for the tp_compare slot is updated to require that
655 the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
656 not correct. This is not yet enforced but will be enforced in
657 Python 2.3; even later, we may use -2 to indicate errors and +2 for
658 "NotImplemented". Right now, -1 should be used for an error return.
659
Tim Petersd38b1c72001-09-30 05:09:37 +0000660- PyLong_AsLongLong() now accepts int (as well as long) arguments.
661 Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
662 as long) arguments.
663
Guido van Rossum3c288632001-10-16 21:13:49 +0000664- PyThread_start_new_thread() now returns a long int giving the thread
665 ID, if one can be calculated; it returns -1 for error, 0 if no
666 thread ID is calculated (this is an incompatible change, but only
667 the thread module used this API). This code has only really been
668 tested on Linux and Windows; other platforms please beware (and
669 report any bugs or strange behavior).
670
Guido van Rossum1c486092001-10-19 02:05:35 +0000671- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
672 input.
673
Tim Petersabf925f2001-09-28 21:53:42 +0000674New platforms
675
676Tests
677
678Windows
679
Tim Peters04cf1d32001-10-09 22:39:40 +0000680- Installer: If you install IDLE, and don't disable file-extension
681 registration, a new "Edit with IDLE" context (right-click) menu entry
682 is created for .py and .pyw files.
683
Tim Peters1ce3cf72001-10-01 17:58:40 +0000684- The signal module now supports SIGBREAK on Windows, thanks to Steven
685 Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
686 action remains to call Win32 ExitProcess(). This can be changed via
687 signal.signal(). For example:
688
689 # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
690 # (SIGINT) behavior.
691 import signal
692 signal.signal(signal.SIGBREAK,
693 signal.default_int_handler)
694
695 try:
696 while 1:
697 pass
698 except KeyboardInterrupt:
699 # We get here on Ctrl+C or Ctrl+Break now; if we had not changed
700 # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
701 # program without the possibility for any Python-level cleanup).
702 print "Clean exit"
703
Tim Petersabf925f2001-09-28 21:53:42 +0000704
Tim Petersb07352e2001-09-08 01:25:47 +0000705What's New in Python 2.2a4?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000706Release date: 28-Sep-2001
Tim Petersb07352e2001-09-08 01:25:47 +0000707===========================
708
Guido van Rossum808eea72001-09-25 04:15:41 +0000709Type/class unification and new-style classes
710
711- pydoc and inspect are now aware of new-style classes;
712 e.g. help(list) at the interactive prompt now shows proper
713 documentation for all operations on list objects.
714
715- Applications using Jim Fulton's ExtensionClass module can now safely
716 be used with Python 2.2. In particular, Zope 2.4.1 now works with
717 Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
718 examples also work again. It is hoped that Gtk and Boost also work
719 with 2.2a4 and beyond. (If you can confirm this, please write
720 webmaster@python.org; if there are still problems, please open a bug
721 report on SourceForge.)
Tim Petersb07352e2001-09-08 01:25:47 +0000722
Tim Peters66c1a522001-09-24 21:17:50 +0000723- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
724 These map to readonly attributes 'fget', 'fset', 'fdel', and '__doc__'
725 in the constructed property object. fget, fset and fdel weren't
726 discoverable from Python in 2.2a3. __doc__ is new, and allows to
727 associate a docstring with a property.
728
Guido van Rossum808eea72001-09-25 04:15:41 +0000729- Comparison overloading is now more completely implemented. For
730 example, a str subclass instance can properly be compared to a str
731 instance, and it can properly overload comparison. Ditto for most
732 other built-in object types.
733
734- The repr() of new-style classes has changed; instead of <type
735 'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
736 *except* for built-in types, which are still rendered as <type
737 'Foo'> (to avoid upsetting existing code that might parse or
738 otherwise rely on repr() of certain type objects).
739
740- The repr() of new-style objects is now always <Foo object at XXX>;
741 previously, it was sometimes <Foo instance at XXX>.
742
743- For new-style classes, what was previously called __getattr__ is now
744 called __getattribute__. This method, if defined, is called for
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000745 *every* attribute access. A new __getattr__ hook more similar to the
Guido van Rossum808eea72001-09-25 04:15:41 +0000746 one in classic classes is defined which is called only if regular
747 attribute access raises AttributeError; to catch *all* attribute
748 access, you can use __getattribute__ (for new-style classes). If
749 both are defined, __getattribute__ is called first, and if it raises
750 AttributeError, __getattr__ is called.
751
752- The __class__ attribute of new-style objects can be assigned to.
753 The new class must have the same C-level object layout as the old
754 class.
755
756- The builtin file type can be subclassed now. In the usual pattern,
757 "file" is the name of the builtin type, and file() is a new builtin
758 constructor, with the same signature as the builtin open() function.
759 file() is now the preferred way to open a file.
760
761- Previously, __new__ would only see sequential arguments passed to
762 the type in a constructor call; __init__ would see both sequential
763 and keyword arguments. This made no sense whatsoever any more, so
764 now both __new__ and __init__ see all arguments.
765
766- Previously, hash() applied to an instance of a subclass of str or
767 unicode always returned 0. This has been repaired.
768
769- Previously, an operation on an instance of a subclass of an
770 immutable type (int, long, float, complex, tuple, str, unicode),
771 where the subtype didn't override the operation (and so the
772 operation was handled by the builtin type), could return that
773 instance instead a value of the base type. For example, if s was of
774 a str sublass type, s[:] returned s as-is. Now it returns a str
775 with the same value as s.
776
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000777- Provisional support for pickling new-style objects has been added.
778
Guido van Rossum808eea72001-09-25 04:15:41 +0000779Core
780
Tim Peters2c9aa5e2001-09-23 04:06:05 +0000781- file.writelines() now accepts any iterable object producing strings.
782
Marc-André Lemburgaefd7662001-09-20 12:59:37 +0000783- PyUnicode_FromEncodedObject() now works very much like
784 PyObject_Str(obj) in that it tries to use __str__/tp_str
785 on the object if the object is not a string or buffer. This
786 makes unicode() behave like str() when applied to non-string/buffer
787 objects.
788
Andrew M. Kuchling51c18162001-10-22 01:47:26 +0000789- PyFile_WriteObject now passes Unicode objects to the file's write
790 method. As a result, all file-like objects which may be the target
Martin v. Löwis2777c022001-09-19 13:47:32 +0000791 of a print statement must support Unicode objects, i.e. they must
792 at least convert them into ASCII strings.
793
Guido van Rossum624c8af2001-09-18 15:21:04 +0000794- Thread scheduling on Solaris should be improved; it is no longer
795 necessary to insert a small sleep at the start of a thread in order
796 to let other runnable threads be scheduled.
797
Tim Petersb07352e2001-09-08 01:25:47 +0000798Library
799
Marc-André Lemburgbf990172001-09-27 14:17:33 +0000800- StringIO.StringIO instances and cStringIO.StringIO instances support
801 read character buffer compatible objects for their .write() methods.
802 These objects are converted to strings and then handled as such
803 by the instances.
804
Barry Warsaw2f600732001-09-24 04:28:10 +0000805- The "email" package has been added. This is basically a port of the
806 mimelib package <http://sf.net/projects/mimelib> with API changes
807 and some implementations updated to use iterators and generators.
808
Tim Peters8a9c2842001-09-22 21:30:22 +0000809- difflib.ndiff() and difflib.Differ.compare() are generators now. This
810 restores the ability of Tools/scripts/ndiff.py to start producing output
811 before the entire comparison is complete.
812
Barry Warsaw58b072d2001-09-22 04:44:21 +0000813- StringIO.StringIO instances and cStringIO.StringIO instances support
814 iteration just like file objects (i.e. their .readline() method is
815 called for each iteration until it returns an empty string).
816
Marc-André Lemburg494f2ae2001-09-19 11:33:31 +0000817- The codecs module has grown four new helper APIs to access
818 builtin codecs: getencoder(), getdecoder(), getreader(),
819 getwriter().
820
Guido van Rossum624c8af2001-09-18 15:21:04 +0000821- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
822 simplifies writing XML RPC servers.
823
Barry Warsaw647d5e82001-09-28 17:01:02 +0000824- os.path.realpath(): a new function that returns the absolute pathname
Guido van Rossum624c8af2001-09-18 15:21:04 +0000825 after interpretation of symbolic links. On non-Unix systems, this
826 is an alias for os.path.abspath().
827
Tim Peters16a77ad2001-09-08 04:00:12 +0000828- operator.indexOf() (PySequence_Index() in the C API) now works with any
829 iterable object.
830
Guido van Rossum624c8af2001-09-18 15:21:04 +0000831- smtplib now supports various authentication and security features of
832 the SMTP protocol through the new login() and starttls() methods.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000833
Guido van Rossum624c8af2001-09-18 15:21:04 +0000834- hmac: a new module implementing keyed hashing for message
835 authentication.
836
837- mimetypes now recognizes more extensions and file types. At the
838 same time, some mappings not sanctioned by IANA were removed.
Guido van Rossumd8185ca2001-09-14 16:35:16 +0000839
Guido van Rossum624c8af2001-09-18 15:21:04 +0000840- The "compiler" package has been brought up to date to the state of
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000841 Python 2.2 bytecode generation. It has also been promoted from a
842 Tool to a standard library package. (Tools/compiler still exists as
843 a sample driver.)
844
Guido van Rossumc9ed5dc2001-09-20 05:30:24 +0000845Tools
Guido van Rossum624c8af2001-09-18 15:21:04 +0000846
Tim Petersb07352e2001-09-08 01:25:47 +0000847Build
848
Guido van Rossum624c8af2001-09-18 15:21:04 +0000849- Large file support (LFS) is now automatic when the platform supports
850 it; no more manual configuration tweaks are needed. On Linux, at
851 least, it's possible to have a system whose C library supports large
852 files but whose kernel doesn't; in this case, large file support is
853 still enabled but doesn't do you any good unless you upgrade your
854 kernel or share your Python executable with another system whose
855 kernel has large file support.
856
857- The configure script now supplies plausible defaults in a
858 cross-compilation environment. This doesn't mean that the supplied
859 values are always correct, or that cross-compilation now works
860 flawlessly -- but it's a first step (and it shuts up most of
861 autoconf's warnings about AC_TRY_RUN).
862
863- The Unix build is now a bit less chatty, courtesy of the parser
864 generator. The build is completely silent (except for errors) when
865 using "make -s", thanks to a -q option to setup.py.
866
Tim Petersb07352e2001-09-08 01:25:47 +0000867C API
868
Guido van Rossum624c8af2001-09-18 15:21:04 +0000869- The "structmember" API now supports some new flag bits to deny read
870 and/or write access to attributes in restricted execution mode.
871
Tim Petersb07352e2001-09-08 01:25:47 +0000872New platforms
873
Guido van Rossum624c8af2001-09-18 15:21:04 +0000874- Compaq's iPAQ handheld, running the "familiar" Linux distribution
875 (http://familiar.handhelds.org).
876
Tim Petersb07352e2001-09-08 01:25:47 +0000877Tests
878
Tim Peters8a9c2842001-09-22 21:30:22 +0000879- The "classic" standard tests, which work by comparing stdout to
880 an expected-output file under Lib/test/output/, no longer stop at
881 the first mismatch. Instead the test is run to completion, and a
882 variant of ndiff-style comparison is used to report all differences.
883 This is much easier to understand than the previous style of reporting.
884
885- The unittest-based standard tests now use regrtest's test_main()
886 convention, instead of running as a side-effect of merely being
887 imported. This allows these tests to be run in more natural and
888 flexible ways as unittests, outside the regrtest framework.
889
890- regrtest.py is much better integrated with unittest and doctest now,
891 especially in regard to reporting errors.
892
Tim Petersb07352e2001-09-08 01:25:47 +0000893Windows
894
Guido van Rossum624c8af2001-09-18 15:21:04 +0000895- Large file support now also works for files > 4GB, on filesystems
Tim Peters8a9c2842001-09-22 21:30:22 +0000896 that support it (NTFS under Windows 2000). See "What's New in
897 Python 2.2a3" for more detail.
Guido van Rossum624c8af2001-09-18 15:21:04 +0000898
Tim Petersb07352e2001-09-08 01:25:47 +0000899
Tim Petersedc99312001-08-22 21:36:50 +0000900What's New in Python 2.2a3?
Barry Warsaw86fbaf82001-09-28 15:26:12 +0000901Release Date: 07-Sep-2001
Tim Petersedc99312001-08-22 21:36:50 +0000902===========================
903
904Core
905
Tim Peters9fffa3e2001-09-04 05:14:19 +0000906- Conversion of long to float now raises OverflowError if the long is too
907 big to represent as a C double.
908
Tim Peters32f453e2001-09-03 08:35:41 +0000909- The 3-argument builtin pow() no longer allows a third non-None argument
910 if either of the first two arguments is a float, or if both are of
911 integer types and the second argument is negative (in which latter case
912 the arguments are converted to float, so this is really the same
913 restriction).
914
Tim Peters5d2b77c2001-09-03 05:47:38 +0000915- The builtin dir() now returns more information, and sometimes much
916 more, generally naming all attributes of an object, and all attributes
917 reachable from the object via its class, and from its class's base
918 classes, and so on from them too. Example: in 2.2a2, dir([]) returned
919 an empty list. In 2.2a3,
920
921 >>> dir([])
922 ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
923 '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
924 '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
925 '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
926 '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
927 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
928 'reverse', 'sort']
929
930 dir(module) continues to return only the module's attributes, though.
931
Tim Petersbdee63f2001-09-02 03:40:59 +0000932- Overflowing operations on plain ints now return a long int rather
Guido van Rossumae457142001-08-31 18:31:35 +0000933 than raising OverflowError. This is a partial implementation of PEP
934 237. You can use -Wdefault::OverflowWarning to enable a warning for
935 this situation, and -Werror::OverflowWarning to revert to the old
936 OverflowError exception.
937
Guido van Rossum61c345f2001-09-04 03:26:15 +0000938- A new command line option, -Q<arg>, is added to control run-time
Guido van Rossumae457142001-08-31 18:31:35 +0000939 warnings for the use of classic division. (See PEP 238.) Possible
Barry Warsawd6c8ca62001-09-07 18:13:44 +0000940 values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
941 -Qold, meaning the / operator has its classic meaning and no
942 warnings are issued. Using -Qwarn issues a run-time warning about
943 all uses of classic division for int and long arguments; -Qwarnall
944 also warns about classic division for float and complex arguments
Tim Peters3caca232001-12-06 06:23:26 +0000945 (for use with fixdiv.py).
946 [Note: the remainder of this paragraph (preserved below) became
947 obsolete in 2.2c1 -- -Qnew has global effect in 2.2]
948 <obsolete>
949 Using -Qnew is questionable; it turns on new division by default, but
950 only in the __main__ module. You can usefully combine -Qwarn or
951 -Qwarnall and -Qnew: this gives the __main__ module new division, and
952 warns about classic division everywhere else.
953 </obsolete>
Guido van Rossumae457142001-08-31 18:31:35 +0000954
Tim Petersbdee63f2001-09-02 03:40:59 +0000955- Many built-in types can now be subclassed. This applies to int,
Guido van Rossumae457142001-08-31 18:31:35 +0000956 long, float, str, unicode, and tuple. (The types complex, list and
957 dictionary can also be subclassed; this was introduced earlier.)
958 Note that restrictions apply when subclassing immutable built-in
959 types: you can only affect the value of the instance by overloading
960 __new__. You can add mutable attributes, and the subclass instances
961 will have a __dict__ attribute, but you cannot change the "value"
962 (as implemented by the base class) of an immutable subclass instance
963 once it is created.
964
Guido van Rossumaaf80c82001-09-02 13:44:35 +0000965- The dictionary constructor now takes an optional argument, a
966 mapping-like object, and initializes the dictionary from its
967 (key, value) pairs.
968
Tim Petersbdee63f2001-09-02 03:40:59 +0000969- A new built-in type, super, has been added. This facilitates making
Guido van Rossumae457142001-08-31 18:31:35 +0000970 "cooperative super calls" in a multiple inheritance setting. For an
971 explanation, see http://www.python.org/2.2/descrintro.html#cooperation
972
Guido van Rossum8d7234d2001-09-06 22:02:58 +0000973- A new built-in type, property, has been added. This enables the
974 creation of "properties". These are attributes implemented by
975 getter and setter functions (or only one of these for read-only or
976 write-only attributes), without the need to override __getattr__.
977 See http://www.python.org/2.2/descrintro.html#property
Guido van Rossumae457142001-08-31 18:31:35 +0000978
Tim Petersbdee63f2001-09-02 03:40:59 +0000979- The syntax of floating-point and imaginary literals has been
Tim Petersd507dab2001-08-30 20:51:59 +0000980 liberalized, to allow leading zeroes. Examples of literals now
981 legal that were SyntaxErrors before:
982
983 00.0 0e3 0100j 07.5 00000000000000000008.
984
Tim Petersbdee63f2001-09-02 03:40:59 +0000985- An old tokenizer bug allowed floating point literals with an incomplete
Tim Petersc6d95812001-08-28 20:56:27 +0000986 exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
987
Tim Petersedc99312001-08-22 21:36:50 +0000988Library
989
Martin v. Löwiscb227c92001-09-06 08:54:16 +0000990- telnetlib includes symbolic names for the options, and support for
991 setting an option negotiation callback.
992
Tim Petersa40c7932001-09-05 22:36:56 +0000993- The new C standard no longer requires that math libraries set errno to
994 ERANGE on overflow. For platform libraries that exploit this new
995 freedom, Python's overflow-checking was wholly broken. A new overflow-
996 checking scheme attempts to repair that, but may not be reliable on all
997 platforms (C doesn't seem to provide anything both useful and portable
998 in this area anymore).
999
Martin v. Löwis44f86962001-09-05 13:44:54 +00001000- Asynchronous timeout actions are available through the new class
1001 threading.Timer.
1002
Tim Peters78526162001-09-05 00:53:45 +00001003- math.log and math.log10 now return sensible results for even huge
1004 long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
1005
Tim Petersbdee63f2001-09-02 03:40:59 +00001006- A new function, imp.lock_held(), returns 1 when the import lock is
Tim Peters69232342001-08-30 05:16:13 +00001007 currently held. See the docs for the imp module.
1008
Tim Petersbdee63f2001-09-02 03:40:59 +00001009- pickle, cPickle and marshal on 32-bit platforms can now correctly read
Tim Peters82112372001-08-29 02:28:42 +00001010 dumps containing ints written on platforms where Python ints are 8 bytes.
1011 When read on a box where Python ints are 4 bytes, such values are
1012 converted to Python longs.
1013
Tim Petersbdee63f2001-09-02 03:40:59 +00001014- In restricted execution mode (using the rexec module), unmarshalling
Guido van Rossumae457142001-08-31 18:31:35 +00001015 code objects is no longer allowed. This plugs a security hole.
1016
Steve Purcell6091cd62001-09-06 16:05:17 +00001017- unittest.TestResult instances no longer store references to tracebacks
1018 generated by test failures. This prevents unexpected dangling references
1019 to objects that should be garbage collected between tests.
1020
Tim Petersedc99312001-08-22 21:36:50 +00001021Tools
1022
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001023- Tools/scripts/fixdiv.py has been added which can be used to fix
1024 division operators as per PEP 238.
1025
Tim Petersedc99312001-08-22 21:36:50 +00001026Build
1027
Barry Warsawd6c8ca62001-09-07 18:13:44 +00001028- If you are an adventurous person using Mac OS X you may want to look at
1029 Mac/OSX. There is a Makefile there that will build Python as a real Mac
1030 application, which can be used for experimenting with Carbon or Cocoa.
1031 Discussion of this on pythonmac-sig, please.
1032
Tim Peters7eea37e2001-09-04 22:08:56 +00001033C API
1034
1035- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
Tim Peters69232342001-08-30 05:16:13 +00001036
Tim Peters9fffa3e2001-09-04 05:14:19 +00001037- Note that PyLong_AsDouble can fail! This has always been true, but no
1038 callers checked for it. It's more likely to fail now, because overflow
1039 errors are properly detected now. The proper way to check:
1040
1041 double x = PyLong_AsDouble(some_long_object);
1042 if (x == -1.0 && PyErr_Occurred()) {
1043 /* The conversion failed. */
1044 }
1045
Tim Petersbdee63f2001-09-02 03:40:59 +00001046- The GC API has been changed. Extensions that use the old API will still
Neil Schemenauer4042c692001-08-30 15:38:01 +00001047 compile but will not participate in GC. To upgrade an extension
1048 module:
1049
1050 - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
Tim Petersd507dab2001-08-30 20:51:59 +00001051
Neil Schemenauer4042c692001-08-30 15:38:01 +00001052 - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
1053 PyObject_GC_Del to deallocate them
Tim Petersd507dab2001-08-30 20:51:59 +00001054
Neil Schemenauer4042c692001-08-30 15:38:01 +00001055 - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
1056 to PyObject_GC_UnTrack
Tim Petersd507dab2001-08-30 20:51:59 +00001057
Neil Schemenauer4042c692001-08-30 15:38:01 +00001058 - remove PyGC_HEAD_SIZE from object size calculations
1059
1060 - remove calls to PyObject_AS_GC and PyObject_FROM_GC
1061
Tim Petersbdee63f2001-09-02 03:40:59 +00001062- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
Guido van Rossumae457142001-08-31 18:31:35 +00001063 These can be used safely to construct string objects from a
1064 sprintf-style format string (similar to the format string supported
1065 by PyErr_Format()).
Tim Peters69232342001-08-30 05:16:13 +00001066
Tim Petersedc99312001-08-22 21:36:50 +00001067New platforms
1068
Tim Petersb7da0902001-09-02 23:01:43 +00001069- Stephen Hansen contributed patches sufficient to get a clean compile
1070 under Borland C (Windows), but he reports problems running it and ran
1071 out of time to complete the port. Volunteers? Expect a MemoryError
1072 when importing the types module; this is probably shallow, and
1073 causing later failures too.
Tim Petersbdee63f2001-09-02 03:40:59 +00001074
Tim Petersedc99312001-08-22 21:36:50 +00001075Tests
1076
1077Windows
1078
Tim Peters6e13a562001-09-06 00:32:15 +00001079- Large file support is now enabled on Win32 platforms as well as on
1080 Win64. This means that, for example, you can use f.tell() and f.seek()
1081 to manipulate files larger than 2 gigabytes (provided you have enough
1082 disk space, and are using a Windows filesystem that supports large
Tim Peters9a9471c2001-09-11 23:18:51 +00001083 partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
1084 filesize limit, and large file support makes no difference there.
1085 FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
1086 NTFS has no practical limit on file size, and files of any size can be
1087 used from Python now.
Tim Peters6e13a562001-09-06 00:32:15 +00001088
Tim Petersbdee63f2001-09-02 03:40:59 +00001089- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
Tim Peters402d5982001-08-27 06:37:48 +00001090 points to command.com (patch from Brian Quinlan).
1091
Tim Petersedc99312001-08-22 21:36:50 +00001092
Tim Peters20f51a72001-07-21 02:31:40 +00001093What's New in Python 2.2a2?
Barry Warsaw86fbaf82001-09-28 15:26:12 +00001094Release Date: 22-Aug-2001
Tim Peters20f51a72001-07-21 02:31:40 +00001095===========================
1096
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001097Build
1098
Barry Warsaw18b2ecf2001-08-22 20:26:56 +00001099- Tim Peters developed a brand new Windows installer using Wise 8.1,
1100 generously donated to us by Wise Solutions.
1101
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001102- configure supports a new option --enable-unicode, with the values
1103 ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
1104 type and supporting code is completely removed from the interpreter.
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001105
Jack Jansen32ce0cd2001-08-21 19:28:20 +00001106- A new configure option --enable-framework builds a Mac OS X framework,
1107 which "make frameworkinstall" will install. This provides a starting
1108 point for more mac-like functionality, join pythonmac-sig@python.org
1109 if you are interested in helping.
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001110
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001111- The NeXT platform is no longer supported.
1112
1113- The `new' module is now statically linked.
1114
Tim Peters0afb6092001-08-15 06:06:44 +00001115Tools
1116
1117- The new Tools/scripts/cleanfuture.py can be used to automatically
Andrew M. Kuchlingb0532092001-08-15 15:54:56 +00001118 edit out obsolete future statements from Python source code. See
Tim Peters0afb6092001-08-15 06:06:44 +00001119 the module docstring for details.
1120
Tim Peters20f51a72001-07-21 02:31:40 +00001121Tests
1122
Tim Peters5e824c32001-08-12 22:25:01 +00001123- regrtest.py now knows which tests are expected to be skipped on some
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001124 platforms, allowing to give clearer test result output. regrtest
1125 also has optional --use/-u switch to run normally disabled tests
1126 which require network access or consume significant disk resources.
Tim Peters5e824c32001-08-12 22:25:01 +00001127
Tim Peters20f51a72001-07-21 02:31:40 +00001128- Several new tests in the standard test suite, with special thanks to
1129 Nick Mathewson.
1130
1131Core
1132
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001133- The floor division operator // has been added as outlined in PEP
1134 238. The / operator still provides classic division (and will until
1135 Python 3.0) unless "from __future__ import division" is included, in
1136 which case the / operator will provide true division. The operator
1137 module provides truediv() and floordiv() functions. Augmented
1138 assignment variants are included, as are the equivalent overloadable
1139 methods and C API methods. See the PEP for a full discussion:
1140 <http://python.sf.net/peps/pep-0238.html>
1141
Tim Peters6cd6a822001-08-17 22:11:27 +00001142- Future statements are now effective in simulated interactive shells
1143 (like IDLE). This should "just work" by magic, but read Michael
1144 Hudson's "Future statements in simulated shells" PEP 264 for full
1145 details: <http://python.sf.net/peps/pep-0264.html>.
1146
Guido van Rossumf86ddd22001-08-17 21:21:04 +00001147- The type/class unification (PEP 252-253) was integrated into the
1148 trunk and is not so tentative any more (the exact specification of
1149 some features is still tentative). A lot of work has done on fixing
1150 bugs and adding robustness and features (performance still has to
1151 come a long way).
1152
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001153- Warnings about a mismatch in the Python API during extension import
1154 now use the Python warning framework (which makes it possible to
1155 write filters for these warnings).
1156
Barry Warsaw9b3be7f2001-08-14 18:35:02 +00001157- A function's __dict__ (aka func_dict) will now always be a
1158 dictionary. It used to be possible to delete it or set it to None,
1159 but now both actions raise TypeErrors. It is still legal to set it
1160 to a dictionary object. Getting func.__dict__ before any attributes
1161 have been assigned now returns an empty dictionary instead of None.
1162
Guido van Rossum32aa5d22001-09-05 18:43:35 +00001163- A new command line option, -E, was added which disables the use of
1164 all environment variables, or at least those that are specifically
1165 significant to Python. Usually those have a name starting with
1166 "PYTHON". This was used to fix a problem where the tests fail if
1167 the user happens to have PYTHONHOME or PYTHONPATH pointing to an
1168 older distribution.
1169
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001170Library
1171
Tim Peters5e824c32001-08-12 22:25:01 +00001172- New class Differ and new functions ndiff() and restore() in difflib.py.
1173 These package the algorithms used by the popular Tools/scripts/ndiff.py,
Tim Peters0afb6092001-08-15 06:06:44 +00001174 for programmatic reuse.
Tim Peters5e824c32001-08-12 22:25:01 +00001175
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001176- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
1177 value using the minimal quoting required for the value; more
1178 reliable than using xml.sax.saxutils.escape() for attribute values.
1179
1180- Readline completion support for cmd.Cmd was added.
1181
Barry Warsaw6f3410d2001-08-22 04:08:41 +00001182- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
1183
1184- Added function threading.BoundedSemaphore()
1185
1186- Added Ka-Ping Yee's cgitb.py module.
1187
1188- The `new' module now exposes the CO_xxx flags.
1189
Martin v. Löwis560da622001-11-24 09:24:51 +00001190- The gc module offers the get_referents function.
1191
Marc-André Lemburgd6277912001-07-31 14:42:42 +00001192New platforms
1193
1194C API
1195
Marc-André Lemburg888fac02001-07-31 14:24:31 +00001196- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
1197 which provide a cross-platform implementations for the
1198 relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
1199 the standard sprintf() and vsprintf() C lib APIs, these versions
1200 apply bounds checking on the used buffer which enhances protection
1201 against buffer overruns.
1202
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001203- Unicode APIs now use name mangling to assure that mixing interpreters
Tim Petersc1731372001-08-04 08:12:36 +00001204 and extensions using different Unicode widths is rendered next to
1205 impossible. Trying to import an incompatible Unicode-aware extension
Marc-André Lemburg48dbfe92001-07-31 14:37:40 +00001206 will result in an ImportError. Unicode extensions writers must make
1207 sure to check the Unicode width compatibility in their extensions by
1208 using at least one of the mangled Unicode APIs in the extension.
1209
Martin v. Löwis339d0f72001-08-17 18:39:25 +00001210- Two new flags METH_NOARGS and METH_O are available in method definition
1211 tables to simplify implementation of methods with no arguments and a
1212 single untyped argument. Calling such methods is more efficient than
1213 calling corresponding METH_VARARGS methods. METH_OLDARGS is now
1214 deprecated.
1215
Tim Petersc1731372001-08-04 08:12:36 +00001216Windows
1217
1218- "import module" now compiles module.pyw if it exists and nothing else
1219 relevant is found.
1220
Tim Peters20f51a72001-07-21 02:31:40 +00001221
Guido van Rossum55a78992001-07-17 17:22:32 +00001222What's New in Python 2.2a1?
Barry Warsawd970fe42001-10-25 21:53:30 +00001223Release date: 18-Jul-2001
Tim Petersf553f892001-05-01 20:45:31 +00001224===========================
1225
1226Core
Tim Petersa814db52001-05-14 07:05:58 +00001227
Tim Peters6d6c1a32001-08-02 04:15:00 +00001228- TENTATIVELY, a large amount of code implementing much of what's
1229 described in PEP 252 (Making Types Look More Like Classes) and PEP
1230 253 (Subtyping Built-in Types) was added. This will be released
1231 with Python 2.2a1. Documentation will be provided separately
1232 through http://www.python.org/2.2/. The purpose of releasing this
1233 with Python 2.2a1 is to test backwards compatibility. It is
1234 possible, though not likely, that a decision is made not to release
1235 this code as part of 2.2 final, if any serious backwards
1236 incompapatibilities are found during alpha testing that cannot be
1237 repaired.
1238
Guido van Rossum55a78992001-07-17 17:22:32 +00001239- Generators were added; this is a new way to create an iterator (see
Tim Peters11a0d102001-07-17 18:48:00 +00001240 below) using what looks like a simple function containing one or
Guido van Rossum55a78992001-07-17 17:22:32 +00001241 more 'yield' statements. See PEP 255. Since this adds a new
1242 keyword to the language, this feature must be enabled by including a
1243 future statement: "from __future__ import generators" (see PEP 236).
1244 Generators will become a standard feature in a future release
1245 (probably 2.3). Without this future statement, 'yield' remains an
1246 ordinary identifier, but a warning is issued each time it is used.
1247 (These warnings currently don't conform to the warnings framework of
1248 PEP 230; we intend to fix this in 2.2a2.)
1249
Marc-André Lemburg12e74b32001-05-22 08:58:23 +00001250- The UTF-16 codec was modified to be more RFC compliant. It will now
1251 only remove BOM characters at the start of the string and then
1252 only if running in native mode (UTF-16-LE and -BE won't remove a
1253 leading BMO character).
1254
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001255- Strings now have a new method .decode() to complement the already
1256 existing .encode() method. These two methods provide direct access
1257 to the corresponding decoders and encoders of the registered codecs.
1258
1259 To enhance the usability of the .encode() method, the special
1260 casing of Unicode object return values was dropped (Unicode objects
1261 were auto-magically converted to string using the default encoding).
Tim Peterseb28ef22001-06-02 05:27:19 +00001262
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001263 Both methods will now return whatever the codec in charge of the
1264 requested encoding returns as object, e.g. Unicode codecs will
1265 return Unicode objects when decoding is requested ("äöü".decode("latin-1")
1266 will return u"äöü"). This enables codec writer to create codecs
1267 for various simple to use conversions.
1268
1269 New codecs were added to demonstrate these new features (the .encode()
1270 and .decode() columns indicate the type of the returned objects):
1271
1272 Name | .encode() | .decode() | Description
1273 ----------------------------------------------------------------------
1274 uu | string | string | UU codec (e.g. for email)
1275 base64 | string | string | base64 codec
Guido van Rossumc3415802001-06-06 13:30:54 +00001276 quopri | string | string | quoted-printable codec
Marc-André Lemburgfab96cc2001-05-15 18:38:45 +00001277 zlib | string | string | zlib compression
1278 hex | string | string | 2-byte hex codec
1279 rot-13 | string | Unicode | ROT-13 Unicode charmap codec
1280
Mark Hammond2a0af792001-05-14 03:09:36 +00001281- Some operating systems now support the concept of a default Unicode
1282 encoding for file system operations. Notably, Windows supports 'mbcs'
1283 as the default. The Macintosh will also adopt this concept in the medium
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001284 term, although the default encoding for that platform will be other than
Mark Hammond2a0af792001-05-14 03:09:36 +00001285 'mbcs'.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001286
1287 On operating system that support non-ASCII filenames, it is common for
Mark Hammond2a0af792001-05-14 03:09:36 +00001288 functions that return filenames (such as os.listdir()) to return Python
1289 string objects pre-encoded using the default file system encoding for
1290 the platform. As this encoding is likely to be different from Python's
1291 default encoding, converting this name to a Unicode object before passing
1292 it back to the Operating System would result in a Unicode error, as Python
Tim Petersa814db52001-05-14 07:05:58 +00001293 would attempt to use its default encoding (generally ASCII) rather than
1294 the default encoding for the file system.
Guido van Rossum1bd797a2001-05-14 13:53:38 +00001295
Tim Petersa814db52001-05-14 07:05:58 +00001296 In general, this change simply removes surprises when working with
1297 Unicode and the file system, making these operations work as you expect,
1298 increasing the transparency of Unicode objects in this context.
Mark Hammond2a0af792001-05-14 03:09:36 +00001299 See [????] for more details, including examples.
Tim Petersf553f892001-05-01 20:45:31 +00001300
Tim Peters61dff2b2001-05-08 15:43:37 +00001301- Float (and complex) literals in source code were evaluated to full
1302 precision only when running from a .py file; the same code loaded from a
1303 .pyc (or .pyo) file could suffer numeric differences starting at about the
1304 12th significant decimal digit. For example, on a machine with IEEE-754
1305 floating arithmetic,
1306
1307 x = 9007199254740992.0
1308 print long(x)
1309
1310 printed 9007199254740992 if run directly from .py, but 9007199254740000
1311 if from a compiled (.pyc or .pyo) file. This was due to marshal using
1312 str(float) instead of repr(float) when building code objects. marshal
1313 now uses repr(float) instead, which should reproduce floats to full
1314 machine precision (assuming the platform C float<->string I/O conversion
1315 functions are of good quality).
1316
1317 This may cause floating-point results to change in some cases, and
1318 usually for the better, but may also cause numerically unstable
1319 algorithms to break.
1320
Tim Peters2f228e72001-05-13 00:19:31 +00001321- The implementation of dicts suffers fewer collisions, which has speed
1322 benefits. However, the order in which dict entries appear in dict.keys(),
1323 dict.values() and dict.items() may differ from previous releases for a
1324 given dict. Nothing is defined about this order, so no program should
1325 rely on it. Nevertheless, it's easy to write test cases that rely on the
1326 order by accident, typically because of printing the str() or repr() of a
1327 dict to an "expected results" file. See Lib/test/test_support.py's new
1328 sortdict(dict) function for a simple way to display a dict in sorted
1329 order.
1330
Tim Peters7a3bfc32001-06-12 01:22:22 +00001331- Many other small changes to dicts were made, resulting in faster
1332 operation along the most common code paths.
1333
Guido van Rossum10315822001-05-01 20:54:30 +00001334- Dictionary objects now support the "in" operator: "x in dict" means
1335 the same as dict.has_key(x).
1336
Barry Warsaw51acc8d2001-06-26 20:12:50 +00001337- The update() method of dictionaries now accepts generic mapping
1338 objects. Specifically the argument object must support the .keys()
1339 and __getitem__() methods. This allows you to say, for example,
1340 {}.update(UserDict())
1341
Guido van Rossum10315822001-05-01 20:54:30 +00001342- Iterators were added; this is a generalized way of providing values
1343 to a for loop. See PEP 234. There's a new built-in function iter()
1344 to return an iterator. There's a new protocol to get the next value
1345 from an iterator using the next() method (in Python) or the
1346 tp_iternext slot (in C). There's a new protocol to get iterators
1347 using the __iter__() method (in Python) or the tp_iter slot (in C).
1348 Iterating (i.e. a for loop) over a dictionary generates its keys.
1349 Iterating over a file generates its lines.
1350
Tim Petersf553f892001-05-01 20:45:31 +00001351- The following functions were generalized to work nicely with iterator
1352 arguments:
Tim Peterse63415e2001-05-08 04:38:29 +00001353 map(), filter(), reduce(), zip()
Tim Peters8572b4f2001-05-06 01:05:02 +00001354 list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
1355 max(), min()
Tim Peters1af03e92001-05-26 19:37:54 +00001356 join() method of strings
1357 extend() method of lists
Tim Peters75f8e352001-05-05 11:33:43 +00001358 'x in y' and 'x not in y' (PySequence_Contains() in C API)
1359 operator.countOf() (PySequence_Count() in C API)
Tim Petersd6d010b2001-06-21 02:49:55 +00001360 right-hand side of assignment statements with multiple targets, such as
1361 x, y, z = some_iterable_object_returning_exactly_3_values
Tim Peters75f8e352001-05-05 11:33:43 +00001362
Tim Petersd85e1022001-05-11 21:51:48 +00001363- Accessing module attributes is significantly faster (for example,
1364 random.random or os.path or yourPythonModule.yourAttribute).
1365
Tim Peterse63415e2001-05-08 04:38:29 +00001366- Comparing dictionary objects via == and != is faster, and now works even
1367 if the keys and values don't support comparisons other than ==.
1368
Tim Peters95bf9392001-05-10 08:32:44 +00001369- Comparing dictionaries in ways other than == and != is slower: there were
1370 insecurities in the dict comparison implementation that could cause Python
1371 to crash if the element comparison routines for the dict keys and/or
1372 values mutated the dicts. Making the code bulletproof slowed it down.
1373
Tim Peterseb28ef22001-06-02 05:27:19 +00001374- Collisions in dicts are resolved via a new approach, which can help
1375 dramatically in bad cases. For example, looking up every key in a dict
Tim Peters7a3bfc32001-06-12 01:22:22 +00001376 d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
Tim Peterseb28ef22001-06-02 05:27:19 +00001377 faster now. Thanks to Christian Tismer for pointing out the cause and
1378 the nature of an effective cure (last December! better late than never).
Tim Peters15d49292001-05-27 07:39:22 +00001379
Tim Peters52e155e2001-06-16 05:42:57 +00001380- repr() is much faster for large containers (dict, list, tuple).
1381
1382
Tim Petersa814db52001-05-14 07:05:58 +00001383Library
1384
Fred Drake960fdf92001-07-20 18:38:26 +00001385- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
1386 were added to the string module. These a locale-indenpendent
1387 constants, unlike letters, lowercase, and uppercase. These are now
1388 use in appropriate locations in the standard library.
1389
Martin v. Löwisf0473d52001-07-18 16:17:16 +00001390- The flags used in dlopen calls can now be configured using
1391 sys.setdlopenflags and queried using sys.getdlopenflags.
1392
Guido van Rossumc7e4aca2001-07-12 11:54:37 +00001393- Fredrik Lundh's xmlrpclib is now a standard library module. This
1394 provides full client-side XML-RPC support. In addition,
1395 Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
1396 one asyncore-based). Thanks to Eric Raymond for the documentation.
1397
Guido van Rossum643d3912001-07-05 14:46:25 +00001398- The xrange() object is simplified: it no longer supports slicing,
1399 repetition, comparisons, efficient 'in' checking, the tolist()
1400 method, or the start, stop and step attributes. See PEP 260.
1401
Martin v. Löwisebf94db2001-06-06 06:25:40 +00001402- A new function fnmatch.filter to filter lists of file names was added.
1403
Barry Warsawffd674d2001-05-22 16:00:10 +00001404- calendar.py uses month and day names based on the current locale.
1405
Guido van Rossum2e0a6542001-05-15 02:14:44 +00001406- strop is now *really* obsolete (this was announced before with 1.6),
1407 and issues DeprecationWarning when used (except for the four items
1408 that are still imported into string.py).
1409
Tim Petersa814db52001-05-14 07:05:58 +00001410- Cookie.py now sorts key+value pairs by key in output strings.
1411
1412- pprint.isrecursive(object) didn't correctly identify recursive objects.
1413 Now it does.
1414
Tim Peters95b3f782001-05-14 18:39:41 +00001415- pprint functions now much faster for large containers (tuple, list, dict).
1416
Tim Peters7b9542a2001-06-10 23:40:19 +00001417- New 'q' and 'Q' format codes in the struct module, corresponding to C
1418 types "long long" and "unsigned long long" (on Windows, __int64). In
1419 native mode, these can be used only when the platform C compiler supports
1420 these types (when HAVE_LONG_LONG is #define'd by the Python config
1421 process), and then they inherit the sizes and alignments of the C types.
Tim Peters7a3bfc32001-06-12 01:22:22 +00001422 In standard mode, 'q' and 'Q' are supported on all platforms, and are
1423 8-byte integral types.
Tim Peters7b9542a2001-06-10 23:40:19 +00001424
Guido van Rossum83213cc2001-06-12 16:48:52 +00001425- The site module installs a new built-in function 'help' that invokes
1426 pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
1427 it displays a message reminding the user to use 'help()' or
1428 'help(object)'.
1429
Tim Petersa814db52001-05-14 07:05:58 +00001430Tests
1431
1432- New test_mutants.py runs dict comparisons where the key and value
1433 comparison operators mutute the dicts randomly during comparison. This
1434 rapidly causes Python to crash under earlier releases (not for the faint
1435 of heart: it can also cause Win9x to freeze or reboot!).
1436
1437- New test_pprint.py verfies that pprint.isrecursive() and
Tim Peters95b3f782001-05-14 18:39:41 +00001438 pprint.isreadable() return sensible results. Also verifies that simple
1439 cases produce correct output.
Tim Petersa814db52001-05-14 07:05:58 +00001440
Tim Peters4324aa32001-05-28 22:30:08 +00001441C API
1442
1443- Removed the unused last_is_sticky argument from the internal
1444 _PyTuple_Resize(). If this affects you, you were cheating.
1445
1446
Guido van Rossum55a78992001-07-17 17:22:32 +00001447======================================================================
1448
1449
Guido van Rossumffe13be2001-04-16 18:46:45 +00001450What's New in Python 2.1 (final)?
1451=================================
1452
1453We only changed a few things since the last release candidate, all in
1454Python library code:
1455
1456- A bug in the locale module was fixed that affected locales which
1457 define no grouping for numeric formatting.
1458
1459- A few bugs in the weakref module's implementations of weak
1460 dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
1461 and the test suite was updated to check for these bugs.
1462
1463- An old bug in the os.path.walk() function (introduced in Python
1464 2.0!) was fixed: a non-existent file would cause an exception
1465 instead of being ignored.
1466
1467- Fixed a few bugs in the new symtable module found by Neil Norwitz's
1468 PyChecker.
1469
1470
Guido van Rossum5b08f132001-04-16 02:05:23 +00001471What's New in Python 2.1c2?
1472===========================
Barry Warsaw11e89c72001-04-11 20:37:57 +00001473
Guido van Rossum5b08f132001-04-16 02:05:23 +00001474A flurry of small changes, and one showstopper fixed in the nick of
1475time made it necessary to release another release candidate. The list
1476here is the *complete* list of patches (except version updates):
Guido van Rossum4fb60362001-04-13 00:46:14 +00001477
Guido van Rossum5b08f132001-04-16 02:05:23 +00001478Core
Guido van Rossum4fb60362001-04-13 00:46:14 +00001479
Guido van Rossum5b08f132001-04-16 02:05:23 +00001480- Tim discovered a nasty bug in the dictionary code, caused by
1481 PyDict_Next() calling dict_resize(), and the GC code's use of
1482 PyDict_Next() violating an assumption in dict_items(). This was
1483 fixed with considerable amounts of band-aid, but the net effect is a
1484 saner and more robust implementation.
1485
1486- Made a bunch of symbols static that were accidentally global.
1487
1488Build and Ports
1489
1490- The setup.py script didn't check for a new enough version of zlib
1491 (1.1.3 is needed). Now it does.
1492
1493- Changed "make clean" target to also remove shared libraries.
1494
1495- Added a more general warning about the SGI Irix optimizer to README.
1496
1497Library
1498
1499- Fix a bug in urllib.basejoin("http://host", "../file.html") which
1500 omitted the slash between host and file.html.
1501
1502- The mailbox module's _Mailbox class contained a completely broken
1503 and undocumented seek() method. Ripped it out.
1504
1505- Fixed a bunch of typos in various library modules (urllib2, smtpd,
1506 sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
1507
1508- Fixed a few last-minute bugs in unittest.
1509
1510Extensions
1511
1512- Reverted the patch to the OpenSSL code in socketmodule.c to support
1513 RAND_status() and the EGD, and the subsequent patch that tried to
1514 fix it for pre-0.9.5 versions; the problem with the patch is that on
1515 some systems it issues a warning whenever socket is imported, and
1516 that's unacceptable.
1517
1518Tests
1519
1520- Fixed the pickle tests to work with "import test.test_pickle".
1521
1522- Tweaked test_locale.py to actually run the test Windows.
1523
1524- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
1525 not "wb" (which is not a valid mode at all).
1526
1527- Fix pstats browser crashes. Import readline if it exists to make
1528 the user interface nicer.
1529
1530- Add "import thread" to the top of test modules that import the
1531 threading module (test_asynchat and test_threadedtempfile). This
1532 prevents test failures caused by a broken threading module resulting
1533 from a previously caught failed import.
1534
1535- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
1536 needed on some platforms (e.g. Solaris 8) when the tests are run
1537 twice in succession.
1538
1539- Skip rather than fail test_sunaudiodev if no audio device is found.
1540
1541
1542What's New in Python 2.1c1?
1543===========================
1544
1545This list was significantly updated when 2.1c2 was released; the 2.1c1
1546release didn't mention most changes that were actually part of 2.1c1:
1547
1548Legal
1549
1550- Copyright was assigned to the Python Software Foundation (PSF) and a
1551 PSF license (very similar to the CNRI license) was added.
1552
1553- The CNRI copyright notice was updated to include 2001.
1554
1555Core
Barry Warsaw11e89c72001-04-11 20:37:57 +00001556
Guido van Rossumc9932722001-04-12 02:31:27 +00001557- After a public outcry, assignment to __debug__ is no longer illegal;
1558 instead, a warning is issued. It will become illegal in 2.2.
1559
Guido van Rossum5b08f132001-04-16 02:05:23 +00001560- Fixed a core dump with "%#x" % 0, and changed the semantics so that
1561 "%#x" now always prepends "0x", even if the value is zero.
1562
1563- Fixed some nits in the bytecode compiler.
1564
1565- Fixed core dumps when calling certain kinds of non-functions.
1566
1567- Fixed various core dumps caused by reference count bugs.
1568
1569Build and Ports
1570
1571- Use INSTALL_SCRIPT to install script files.
1572
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001573- New port: SCO Unixware 7, by Billy G. Allie.
1574
Guido van Rossum5b08f132001-04-16 02:05:23 +00001575- Updated RISCOS port.
1576
1577- Updated BeOS port and notes.
1578
1579- Various other porting problems resolved.
1580
1581Library
1582
1583- The TERMIOS and SOCKET modules are now truly obsolete and
1584 unnecessary. Their symbols are incorporated in the termios and
1585 socket modules.
1586
1587- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
1588 better tests for pickling.
1589
1590- threading: make Condition.wait() robust against KeyboardInterrupt.
1591
1592- zipfile: add support to zipfile to support opening an archive
1593 represented by an open file rather than a file name. Fix bug where
1594 the archive was not properly closed. Fixed a bug in this bugfix
1595 where flush() was called for a read-only file.
1596
1597- imputil: added an uninstall() method to the ImportManager.
1598
1599- Canvas: fixed bugs in lower() and tkraise() methods.
1600
1601- SocketServer: API change (added overridable close_request() method)
1602 so that the TCP server can explicitly close the request.
1603
1604- pstats: Eric Raymond added a simple interactive statistics browser,
1605 invoked when the module is run as a script.
1606
1607- locale: fixed a problem in format().
1608
1609- webbrowser: made it work when the BROWSER environment variable has a
1610 value like "/usr/bin/netscape". Made it auto-detect Konqueror for
1611 KDE 2. Fixed some other nits.
1612
1613- unittest: changes to allow using a different exception than
1614 AssertionError, and added a few more function aliases. Some other
1615 small changes.
1616
1617- urllib, urllib2: fixed redirect problems and a coupleof other nits.
1618
1619- asynchat: fixed a critical bug in asynchat that slipped through the
1620 2.1b2 release. Fixed another rare bug.
1621
1622- Fix some unqualified except: clauses (always a bad code example).
1623
1624XML
1625
1626- pyexpat: new API get_version_string().
1627
1628- Fixed some minidom bugs.
1629
1630Extensions
1631
1632- Fixed a core dump in _weakref. Removed the weakref.mapping()
1633 function (it adds nothing to the API).
1634
1635- Rationalized the use of header files in the readline module, to make
1636 it compile (albeit with some warnings) with the very recent readline
1637 4.2, without breaking for earlier versions.
1638
1639- Hopefully fixed a buffering problem in linuxaudiodev.
1640
1641- Attempted a fix to make the OpenSSL support in the socket module
1642 work again with pre-0.9.5 versions of OpenSSL.
1643
1644Tests
1645
1646- Added a test case for asynchat and asyncore.
1647
1648- Removed coupling between tests where one test failing could break
1649 another.
1650
1651Tools
1652
1653- Ping added an interactive help browser to pydoc, fixed some nits
1654 in the rest of the pydoc code, and added some features to his
1655 inspect module.
1656
1657- An updated python-mode.el version 4.1 which integrates Ken
1658 Manheimer's pdbtrack.el. This makes debugging Python code via pdb
1659 much nicer in XEmacs and Emacs. When stepping through your program
1660 with pdb, in either the shell window or the *Python* window, the
1661 source file and line will be tracked by an arrow. Very cool!
1662
1663- IDLE: syntax warnings in interactive mode are changed into errors.
1664
1665- Some improvements to Tools/webchecker (ignore some more URL types,
Tim Peters0e57abf2001-05-02 07:39:38 +00001666 follow some more links).
Guido van Rossum5b08f132001-04-16 02:05:23 +00001667
1668- Brought the Tools/compiler package up to date.
Guido van Rossum34d37dc2001-04-11 21:03:32 +00001669
Barry Warsaw11e89c72001-04-11 20:37:57 +00001670
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001671What's New in Python 2.1 beta 2?
1672================================
1673
Guido van Rossum053ae352001-03-22 14:17:21 +00001674(Unlisted are many fixed bugs, more documentation, etc.)
1675
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001676Core language, builtins, and interpreter
1677
Guido van Rossum053ae352001-03-22 14:17:21 +00001678- The nested scopes work (enabled by "from __future__ import
1679 nested_scopes") is completed; in particular, the future now extends
1680 into code executed through exec, eval() and execfile(), and into the
1681 interactive interpreter.
1682
1683- When calling a base class method (e.g. BaseClass.__init__(self)),
1684 this is now allowed even if self is not strictly spoken a class
1685 instance (e.g. when using metaclasses or the Don Beaudry hook).
1686
1687- Slice objects are now comparable but not hashable; this prevents
1688 dict[:] from being accepted but meaningless.
1689
1690- Complex division is now calculated using less braindead algorithms.
1691 This doesn't change semantics except it's more likely to give useful
1692 results in extreme cases. Complex repr() now uses full precision
1693 like float repr().
1694
1695- sgmllib.py now calls handle_decl() for simple <!...> declarations.
1696
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001697- It is illegal to assign to the name __debug__, which is set when the
1698 interpreter starts. It is effectively a compile-time constant.
1699
1700- A warning will be issued if a global statement for a variable
1701 follows a use or assignment of that variable.
1702
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001703Standard library
1704
Guido van Rossum053ae352001-03-22 14:17:21 +00001705- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
1706 inspired by JUnit), is now part of the standard library. You now
1707 have a choice of two testing frameworks: unittest requires you to
1708 write testcases as separate code, doctest gathers them from
1709 docstrings. Both approaches have their advantages and
1710 disadvantages.
1711
1712- A new module Tix was added, which wraps the Tix extension library
1713 for Tk. With that module, it is not necessary to statically link
1714 Tix with _tkinter, since Tix will be loaded with Tcl's "package
1715 require" command. See Demo/tix/.
1716
1717- tzparse.py is now obsolete.
1718
1719- In gzip.py, the seek() and tell() methods are removed -- they were
1720 non-functional anyway, and it's better if callers can test for their
1721 existence with hasattr().
1722
1723Python/C API
1724
1725- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
1726 that's already in the dictionary during a PyDict_Next() iteration.
1727 This used to fail occasionally when a dictionary resize operation
1728 could be triggered that would rehash all the keys. All other
1729 modifications to the dictionary are still off-limits during a
1730 PyDict_Next() iteration!
1731
1732- New extended APIs related to passing compiler variables around.
1733
1734- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
1735 implement isinstance() and issubclass().
1736
1737- Py_BuildValue() now has a "D" conversion to create a Python complex
1738 number from a Py_complex C value.
Martin v. Löwis0411f6f2001-03-21 08:01:39 +00001739
Fred Drake4e262a92001-03-22 18:26:47 +00001740- Extensions types which support weak references must now set the
1741 field allocated for the weak reference machinery to NULL themselves;
1742 this is done to avoid the cost of checking each object for having a
1743 weakly referencable type in PyObject_INIT(), since most types are
1744 not weakly referencable.
1745
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001746- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
1747 free variables and cell variables to and from the frame's f_locals.
1748
1749- Variants of several functions defined in pythonrun.h have been added
1750 to support the nested_scopes future statement. The variants all end
1751 in Flags and take an extra argument, a PyCompilerFlags *; examples:
1752 PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
1753 variants may be removed in Python 2.2, when nested scopes are
Tim Peters0e57abf2001-05-02 07:39:38 +00001754 mandatory.
Jeremy Hyltonf626db72001-03-23 14:18:27 +00001755
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001756Distutils
1757
1758- the sdist command now writes a PKG-INFO file, as described in PEP 241,
1759 into the release tree.
1760
Tim Peters0e57abf2001-05-02 07:39:38 +00001761- several enhancements to the bdist_wininst command from Thomas Heller
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001762 (an uninstaller, more customization of the installer's display)
1763
1764- from Jack Jansen: added Mac-specific code to generate a dialog for
1765 users to specify the command-line (because providing a command-line with
Tim Peters0e57abf2001-05-02 07:39:38 +00001766 MacPython is awkward). Jack also made various fixes for the Mac
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001767 and the Metrowerks compiler.
Tim Peters0e57abf2001-05-02 07:39:38 +00001768
1769- added 'platforms' and 'keywords' to the set of metadata that can be
1770 specified for a distribution.
Andrew M. Kuchling8e9972c2001-03-22 15:42:08 +00001771
1772- applied patches from Jason Tishler to make the compiler class work with
1773 Cygwin.
1774
1775
Tim Peters2fe289a2001-03-01 22:19:38 +00001776What's New in Python 2.1 beta 1?
1777================================
Tim Petersd66595f2001-02-04 03:09:53 +00001778
1779Core language, builtins, and interpreter
1780
Guido van Rossum9d0fbde2001-03-02 14:00:32 +00001781- Following an outcry from the community about the amount of code
1782 broken by the nested scopes feature introduced in 2.1a2, we decided
1783 to make this feature optional, and to wait until Python 2.2 (or at
1784 least 6 months) to make it standard. The option can be enabled on a
1785 per-module basis by adding "from __future__ import nested_scopes" at
1786 the beginning of a module (before any other statements, but after
1787 comments and an optional docstring). See PEP 236 (Back to the
1788 __future__) for a description of the __future__ statement. PEP 227
1789 (Statically Nested Scopes) has been updated to reflect this change,
1790 and to clarify the semantics in a number of endcases.
1791
1792- The nested scopes code, when enabled, has been hardened, and most
1793 bugs and memory leaks in it have been fixed.
1794
1795- Compile-time warnings are now generated for a number of conditions
1796 that will break or change in meaning when nested scopes are enabled:
1797
1798 - Using "from...import *" or "exec" without in-clause in a function
1799 scope that also defines a lambda or nested function with one or
1800 more free (non-local) variables. The presence of the import* or
1801 bare exec makes it impossible for the compiler to determine the
1802 exact set of local variables in the outer scope, which makes it
1803 impossible to determine the bindings for free variables in the
1804 inner scope. To avoid the warning about import *, change it into
1805 an import of explicitly name object, or move the import* statement
1806 to the global scope; to avoid the warning about bare exec, use
1807 exec...in... (a good idea anyway -- there's a possibility that
1808 bare exec will be deprecated in the future).
1809
1810 - Use of a global variable in a nested scope with the same name as a
1811 local variable in a surrounding scope. This will change in
1812 meaning with nested scopes: the name in the inner scope will
1813 reference the variable in the outer scope rather than the global
1814 of the same name. To avoid the warning, either rename the outer
1815 variable, or use a global statement in the inner function.
1816
Neil Schemenauera35c6882001-02-27 04:45:05 +00001817- An optional object allocator has been included. This allocator is
1818 optimized for Python objects and should be faster and use less memory
1819 than the standard system allocator. It is not enabled by default
1820 because of possible thread safety problems. The allocator is only
1821 protected by the Python interpreter lock and it is possible that some
1822 extension modules require a thread safe allocator. The object
1823 allocator can be enabled by providing the "--with-pymalloc" option to
1824 configure.
1825
Tim Petersd66595f2001-02-04 03:09:53 +00001826Standard library
1827
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00001828- pyexpat now detects the expat version if expat.h defines it. A
1829 number of additional handlers are provided, which are only available
1830 since expat 1.95. In addition, the methods SetParamEntityParsing and
1831 GetInputContext of Parser objects are available with 1.95.x
1832 only. Parser objects now provide the ordered_attributes and
1833 specified_attributes attributes. A new module expat.model was added,
1834 which offers a number of additional constants if 1.95.x is used.
1835
1836- xml.dom offers the new functions registerDOMImplementation and
1837 getDOMImplementation.
1838
1839- xml.dom.minidom offers a toprettyxml method. A number of DOM
1840 conformance issues have been resolved. In particular, Element now
1841 has an hasAttributes method, and the handling of namespaces was
1842 improved.
1843
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001844- Ka-Ping Yee contributed two new modules: inspect.py, a module for
1845 getting information about live Python code, and pydoc.py, a module
1846 for interactively converting docstrings to HTML or text.
1847 Tools/scripts/pydoc, which is now automatically installed into
Tim Peters1eff7962001-03-01 02:31:33 +00001848 <prefix>/bin, uses pydoc.py to display documentation; try running
Guido van Rossume3955a82001-03-02 14:05:59 +00001849 "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
1850 lets you browse the module docstrings using a web browser.
Andrew M. Kuchlingd6a1d792001-02-28 21:05:42 +00001851
Tim Peters1eff7962001-03-01 02:31:33 +00001852- New library module difflib.py, primarily packaging the SequenceMatcher
1853 class at the heart of the popular ndiff.py file-comparison tool.
1854
1855- doctest.py (a framework for verifying Python code examples in docstrings)
1856 is now part of the std library.
1857
Tim Petersd66595f2001-02-04 03:09:53 +00001858Windows changes
1859
Guido van Rossume3955a82001-03-02 14:05:59 +00001860- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
1861 small GUI that lets you browse the module docstrings using your
1862 default web browser.
1863
Tim Peters1eff7962001-03-01 02:31:33 +00001864- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
1865 Platforms) is implemented. See
1866
1867 http://python.sourceforge.net/peps/pep-0235.html
1868
1869 for full details, especially the "Current Lower-Left Semantics" section.
1870 The new Windows import rules are simpler than before:
1871
1872 A. If the PYTHONCASEOK environment variable exists, same as
1873 before: silently accept the first case-insensitive match of any
1874 kind; raise ImportError if none found.
1875
1876 B. Else search sys.path for the first case-sensitive match; raise
1877 ImportError if none found.
1878
1879 The same rules have been implented on other platforms with case-
1880 insensitive but case-preserving filesystems too (including Cygwin, and
1881 several flavors of Macintosh operating systems).
Tim Petersd66595f2001-02-04 03:09:53 +00001882
Tim Peters25a9ce32001-02-19 07:06:36 +00001883- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
1884 what it's supposed to do (and does do under NT and 2000) via direct
1885 port manipulation. It's unknown whether this will work on all systems,
Tim Peters1eff7962001-03-01 02:31:33 +00001886 but it does work on my Win98SE systems now and was known to be useless on
Tim Peters25a9ce32001-02-19 07:06:36 +00001887 all Win9x systems before.
1888
Tim Peters1eff7962001-03-01 02:31:33 +00001889- Build: Subproject _test (effectively) renamed to _testcapi.
1890
Tim Peters2fe289a2001-03-01 22:19:38 +00001891New platforms
1892
1893- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
1894 Thanks to Steven Majewski!
1895
1896- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
1897 Tishler!
1898
Guido van Rossum9089b272001-03-02 06:49:50 +00001899- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
1900 Schwertberger! See RISCOS/README for more information -- it seems
1901 that because of the bizarre filename conventions on RISCOS, no port
Guido van Rossum49192142001-10-24 20:51:44 +00001902 to that platform is easy.
Guido van Rossum9089b272001-03-02 06:49:50 +00001903
Tim Peters25a9ce32001-02-19 07:06:36 +00001904
Tim Petersd7b5e882001-01-25 03:36:26 +00001905What's New in Python 2.1 alpha 2?
1906=================================
Tim Peters40ead762001-01-27 05:35:26 +00001907
Tim Petersd7b5e882001-01-25 03:36:26 +00001908Core language, builtins, and interpreter
1909
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001910- Scopes nest. If a name is used in a function or class, but is not
1911 local, the definition in the nearest enclosing function scope will
1912 be used. One consequence of this change is that lambda statements
1913 could reference variables in the namespaces where the lambda is
1914 defined. In some unusual cases, this change will break code.
1915
1916 In all previous version of Python, names were resolved in exactly
1917 three namespaces -- the local namespace, the global namespace, and
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001918 the builtin namespace. According to this old definition, if a
Jeremy Hylton4589bd82001-02-01 20:38:45 +00001919 function A is defined within a function B, the names bound in B are
1920 not visible in A. The new rules make names bound in B visible in A,
1921 unless A contains a name binding that hides the binding in B.
1922
1923 Section 4.1 of the reference manual describes the new scoping rules
1924 in detail. The test script in Lib/test/test_scope.py demonstrates
1925 some of the effects of the change.
1926
1927 The new rules will cause existing code to break if it defines nested
1928 functions where an outer function has local variables with the same
1929 name as globals or builtins used by the inner function. Example:
1930
1931 def munge(str):
1932 def helper(x):
1933 return str(x)
1934 if type(str) != type(''):
1935 str = helper(str)
1936 return str.strip()
1937
1938 Under the old rules, the name str in helper() is bound to the
1939 builtin function str(). Under the new rules, it will be bound to
1940 the argument named str and an error will occur when helper() is
1941 called.
1942
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00001943- The compiler will report a SyntaxError if "from ... import *" occurs
1944 in a function or class scope. The language reference has documented
1945 that this case is illegal, but the compiler never checked for it.
1946 The recent introduction of nested scope makes the meaning of this
1947 form of name binding ambiguous. In a future release, the compiler
1948 may allow this form when there is no possibility of ambiguity.
1949
Tim Peters40ead762001-01-27 05:35:26 +00001950- repr(string) is easier to read, now using hex escapes instead of octal,
1951 and using \t, \n and \r instead of \011, \012 and \015 (respectively):
1952
1953 >>> "\texample \r\n" + chr(0) + chr(255)
1954 '\texample \r\n\x00\xff' # in 2.1
1955 '\011example \015\012\000\377' # in 2.0
1956
Moshe Zadka6af0ce02001-01-29 06:41:00 +00001957- Functions are now compared and hashed by identity, not by value, since
1958 the func_code attribute is writable.
1959
Fred Drakefb9d7122001-02-01 20:00:40 +00001960- Weak references (PEP 205) have been added. This involves a few
1961 changes in the core, an extension module (_weakref), and a Python
1962 module (weakref). The weakref module is the public interface. It
1963 includes support for "explicit" weak references, proxy objects, and
1964 mappings with weakly held values.
1965
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001966- A 'continue' statement can now appear in a try block within the body
1967 of a loop. It is still not possible to use continue in a finally
Tim Peters9ea17ac2001-02-02 05:57:15 +00001968 clause.
Jeremy Hylton0072d5a2001-02-01 22:53:15 +00001969
Tim Petersd7b5e882001-01-25 03:36:26 +00001970Standard library
1971
Barry Warsaw30dbd142001-01-31 22:14:01 +00001972- mailbox.py now has a new class, PortableUnixMailbox which is
1973 identical to UnixMailbox but uses a more portable scheme for
1974 determining From_ separators. Also, the constructors for all the
1975 classes in this module have a new optional `factory' argument, which
1976 is a callable used when new message classes must be instantiated by
1977 the next() method.
1978
Tim Petersd7b5e882001-01-25 03:36:26 +00001979- random.py is now self-contained, and offers all the functionality of
1980 the now-deprecated whrandom.py. See the docs for details. random.py
1981 also supports new functions getstate() and setstate(), for saving
Tim Petersd52269b2001-01-25 06:23:18 +00001982 and restoring the internal state of the generator; and jumpahead(n),
1983 for quickly forcing the internal state to be the same as if n calls to
1984 random() had been made. The latter is particularly useful for multi-
1985 threaded programs, creating one instance of the random.Random() class for
1986 each thread, then using .jumpahead() to force each instance to use a
1987 non-overlapping segment of the full period.
Tim Petersd7b5e882001-01-25 03:36:26 +00001988
Tim Peters0de88fc2001-02-01 04:59:18 +00001989- random.py's seed() function is new. For bit-for-bit compatibility with
1990 prior releases, use the whseed function instead. The new seed function
1991 addresses two problems: (1) The old function couldn't produce more than
1992 about 2**24 distinct internal states; the new one about 2**45 (the best
1993 that can be done in the Wichmann-Hill generator). (2) The old function
1994 sometimes produced identical internal states when passed distinct
1995 integers, and there was no simple way to predict when that would happen;
1996 the new one guarantees to produce distinct internal states for all
1997 arguments in [0, 27814431486576L).
1998
Jeremy Hylton4c4fda02001-02-02 03:29:24 +00001999- The socket module now supports raw packets on Linux. The socket
2000 family is AF_PACKET.
2001
Tim Peters9ea17ac2001-02-02 05:57:15 +00002002- test_capi.py is a start at running tests of the Python C API. The tests
2003 are implemented by the new Modules/_testmodule.c.
2004
Jeremy Hyltond6b1cf92001-02-02 20:06:28 +00002005- A new extension module, _symtable, provides provisional access to the
2006 internal symbol table used by the Python compiler. A higher-level
2007 interface will be added on top of _symtable in a future release.
2008
Andrew M. Kuchlingdebc3522001-02-22 15:53:21 +00002009- Removed the obsolete soundex module.
2010
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002011- xml.dom.minidom now uses the standard DOM exceptions. Node supports
2012 the isSameNode method; NamedNodeMap the get method.
2013
2014- xml.sax.expatreader supports the lexical handler property; it
2015 generates comment, startCDATA, and endCDATA events.
2016
Tim Petersee826f82001-01-31 19:39:44 +00002017Windows changes
2018
2019- Build procedure: the zlib project is built in a different way that
2020 ensures the zlib header files used can no longer get out of synch with
Tim Peters9ea17ac2001-02-02 05:57:15 +00002021 the zlib binary used. See PCbuild\readme.txt for details. Your old
2022 zlib-related directories can be deleted; you'll need to download fresh
2023 source for zlib and unpack it into a new directory.
Tim Petersee826f82001-01-31 19:39:44 +00002024
Tim Peters9ea17ac2001-02-02 05:57:15 +00002025- Build: New subproject _test for the benefit of test_capi.py (see above).
2026
Tim Petersb16c56f2001-02-02 21:24:51 +00002027- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
2028 interface to some Python compiler internals).
2029
2030- Build: Subproject ucnhash is gone, since the code was folded into the
Tim Peters9ea17ac2001-02-02 05:57:15 +00002031 unicodedata subproject.
Tim Petersd7b5e882001-01-25 03:36:26 +00002032
Tim Petersa3a3a032000-11-30 05:22:44 +00002033What's New in Python 2.1 alpha 1?
2034=================================
2035
2036Core language, builtins, and interpreter
2037
Marc-André Lemburgebb195b2001-01-20 10:34:52 +00002038- There is a new Unicode companion to the PyObject_Str() API
2039 called PyObject_Unicode(). It behaves in the same way as the
2040 former, but assures that the returned value is an Unicode object
2041 (applying the usual coercion if necessary).
Marc-André Lemburgad7c98e2001-01-17 17:09:53 +00002042
Guido van Rossumf98eda02001-01-17 15:54:45 +00002043- The comparison operators support "rich comparison overloading" (PEP
2044 207). C extension types can provide a rich comparison function in
2045 the new tp_richcompare slot in the type object. The cmp() function
2046 and the C function PyObject_Compare() first try the new rich
2047 comparison operators before trying the old 3-way comparison. There
2048 is also a new C API PyObject_RichCompare() (which also falls back on
2049 the old 3-way comparison, but does not constrain the outcome of the
2050 rich comparison to a Boolean result).
2051
2052 The rich comparison function takes two objects (at least one of
2053 which is guaranteed to have the type that provided the function) and
2054 an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
2055 Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
2056 object, which may be NotImplemented (in which case the tp_compare
2057 slot function is used as a fallback, if defined).
2058
2059 Classes can overload individual comparison operators by defining one
2060 or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
Guido van Rossuma88479f2001-01-18 14:28:08 +00002061 __ge__. There are no explicit "reflected argument" versions of
2062 these; instead, __lt__ and __gt__ are each other's reflection,
2063 likewise for__le__ and __ge__; __eq__ and __ne__ are their own
2064 reflection (similar at the C level). No other implications are
2065 made; in particular, Python does not assume that == is the Boolean
2066 inverse of !=, or that < is the Boolean inverse of >=. This makes
2067 it possible to define types with partial orderings.
Guido van Rossumf98eda02001-01-17 15:54:45 +00002068
2069 Classes or types that want to implement (in)equality tests but not
2070 the ordering operators (i.e. unordered types) should implement ==
2071 and !=, and raise an error for the ordering operators.
2072
Guido van Rossuma88479f2001-01-18 14:28:08 +00002073 It is possible to define types whose rich comparison results are not
Guido van Rossumf98eda02001-01-17 15:54:45 +00002074 Boolean; e.g. a matrix type might want to return a matrix of bits
2075 for A < B, giving elementwise comparisons. Such types should ensure
2076 that any interpretation of their value in a Boolean context raises
2077 an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
2078 at the C level) to always raise an exception.
2079
Guido van Rossuma88479f2001-01-18 14:28:08 +00002080- Complex numbers use rich comparisons to define == and != but raise
2081 an exception for <, <=, > and >=. Unfortunately, this also means
2082 that cmp() of two complex numbers raises an exception when the two
2083 numbers differ. Since it is not mathematically meaningful to compare
2084 complex numbers except for equality, I hope that this doesn't break
2085 too much code.
2086
Tim Peters3389f192001-02-18 08:48:49 +00002087- The outcome of comparing non-numeric objects of different types is
Tim Peters14495852001-02-18 08:28:33 +00002088 not defined by the language, other than that it's arbitrary but
2089 consistent (see the Reference Manual). An implementation detail changed
2090 in 2.1a1 such that None now compares less than any other object. Code
2091 relying on this new behavior (like code that relied on the previous
2092 behavior) does so at its own risk.
2093
Barry Warsaw573b5412001-01-15 20:43:18 +00002094- Functions and methods now support getting and setting arbitrarily
2095 named attributes (PEP 232). Functions have a new __dict__
2096 (a.k.a. func_dict) which hold the function attributes. Methods get
2097 and set attributes on their underlying im_func. It is a TypeError
2098 to set an attribute on a bound method.
2099
Guido van Rossum051e3352001-01-15 19:11:10 +00002100- The xrange() object implementation has been improved so that
2101 xrange(sys.maxint) can be used on 64-bit platforms. There's still a
2102 limitation that in this case len(xrange(sys.maxint)) can't be
2103 calculated, but the common idiom "for i in xrange(sys.maxint)" will
2104 work fine as long as the index i doesn't actually reach 2**31.
2105 (Python uses regular ints for sequence and string indices; fixing
2106 that is much more work.)
2107
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002108- Two changes to from...import:
2109
Guido van Rossumba381232001-02-03 15:06:40 +00002110 1) "from M import X" now works even if (after loading module M)
2111 sys.modules['M'] is not a real module; it's basically a getattr()
2112 operation with AttributeError exceptions changed into ImportError.
Guido van Rossum1cc8f832001-01-12 16:25:08 +00002113
2114 2) "from M import *" now looks for M.__all__ to decide which names to
2115 import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
2116 filters out names starting with '_' as before. Whether or not
2117 __all__ exists, there's no restriction on the type of M.
2118
Guido van Rossumf61f1662001-01-10 20:13:55 +00002119- File objects have a new method, xreadlines(). This is the fastest
2120 way to iterate over all lines in a file:
2121
2122 for line in file.xreadlines():
2123 ...do something to line...
2124
2125 See the xreadlines module (mentioned below) for how to do this for
2126 other file-like objects.
2127
2128- Even if you don't use file.xreadlines(), you may expect a speedup on
2129 line-by-line input. The file.readline() method has been optimized
Tim Petersf29b64d2001-01-15 06:33:19 +00002130 quite a bit in platform-specific ways: on systems (like Linux) that
2131 support flockfile(), getc_unlocked(), and funlockfile(), those are
2132 used by default. On systems (like Windows) without getc_unlocked(),
2133 a complicated (but still thread-safe) method using fgets() is used by
2134 default.
2135
Tim Petersd52269b2001-01-25 06:23:18 +00002136 You can force use of the fgets() method by #define'ing
2137 USE_FGETS_IN_GETLINE at build time (it may be faster than
Tim Petersf29b64d2001-01-15 06:33:19 +00002138 getc_unlocked()).
2139
Tim Petersd52269b2001-01-25 06:23:18 +00002140 You can force fgets() not to be used by #define'ing
2141 DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
Tim Petersf29b64d2001-01-15 06:33:19 +00002142 test_bufio.py fails -- and let us know if it does!).
2143
2144- In addition, the fileinput module, while still slower than the other
2145 methods on most platforms, has been sped up too, by using
2146 file.readlines(sizehint).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002147
2148- Support for run-time warnings has been added, including a new
2149 command line option (-W) to specify the disposition of warnings.
2150 See the description of the warnings module below.
2151
2152- Extensive changes have been made to the coercion code. This mostly
2153 affects extension modules (which can now implement mixed-type
2154 numerical operators without having to use coercion), but
2155 occasionally, in boundary cases the coercion semantics have changed
2156 subtly. Since this was a terrible gray area of the language, this
Guido van Rossumae72d872001-01-11 15:00:14 +00002157 is considered an improvement. Also note that __rcmp__ is no longer
Guido van Rossumf61f1662001-01-10 20:13:55 +00002158 supported -- instead of calling __rcmp__, __cmp__ is called with
Guido van Rossuma88479f2001-01-18 14:28:08 +00002159 reflected arguments.
Guido van Rossumf61f1662001-01-10 20:13:55 +00002160
Guido van Rossumf98eda02001-01-17 15:54:45 +00002161- In connection with the coercion changes, a new built-in singleton
2162 object, NotImplemented is defined. This can be returned for
2163 operations that wish to indicate they are not implemented for a
2164 particular combination of arguments. From C, this is
2165 Py_NotImplemented.
2166
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002167- The interpreter accepts now bytecode files on the command line even
2168 if they do not have a .pyc or .pyo extension. On Linux, after executing
2169
Martin v. Löwise214baa2001-02-04 22:37:56 +00002170import imp,sys,string
2171magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
2172reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
2173open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
Martin v. Löwisbe4c0f52001-01-04 20:30:56 +00002174
2175 any byte code file can be used as an executable (i.e. as an argument
2176 to execve(2)).
2177
Tim Peters9940b802000-12-01 07:59:35 +00002178- %[xXo] formats of negative Python longs now produce a sign
Tim Petersa3a3a032000-11-30 05:22:44 +00002179 character. In 1.6 and earlier, they never produced a sign,
2180 and raised an error if the value of the long was too large
2181 to fit in a Python int. In 2.0, they produced a sign if and
2182 only if too large to fit in an int. This was inconsistent
2183 across platforms (because the size of an int varies across
2184 platforms), and inconsistent with hex() and oct(). Example:
2185
2186 >>> "%x" % -0x42L
Tim Peters9940b802000-12-01 07:59:35 +00002187 '-42' # in 2.1
Tim Petersa3a3a032000-11-30 05:22:44 +00002188 'ffffffbe' # in 2.0 and before, on 32-bit machines
2189 >>> hex(-0x42L)
2190 '-0x42L' # in all versions of Python
2191
Tim Peters9940b802000-12-01 07:59:35 +00002192 The behavior of %d formats for negative Python longs remains
2193 the same as in 2.0 (although in 1.6 and before, they raised
2194 an error if the long didn't fit in a Python int).
2195
2196 %u formats don't make sense for Python longs, but are allowed
2197 and treated the same as %d in 2.1. In 2.0, a negative long
2198 formatted via %u produced a sign if and only if too large to
2199 fit in an int. In 1.6 and earlier, a negative long formatted
2200 via %u raised an error if it was too big to fit in an int.
2201
Guido van Rossum3661d392000-12-12 22:10:31 +00002202- Dictionary objects have an odd new method, popitem(). This removes
2203 an arbitrary item from the dictionary and returns it (in the form of
2204 a (key, value) pair). This can be useful for algorithms that use a
2205 dictionary as a bag of "to do" items and repeatedly need to pick one
2206 item. Such algorithms normally end up running in quadratic time;
2207 using popitem() they can usually be made to run in linear time.
2208
Tim Peters36cdad12000-12-29 02:06:45 +00002209Standard library
2210
Thomas Woutersfe385252001-01-19 23:16:56 +00002211- In the time module, the time argument to the functions strftime,
2212 localtime, gmtime, asctime and ctime is now optional, defaulting to
2213 the current time (in the local timezone).
2214
Guido van Rossumda91f222001-01-15 16:36:08 +00002215- The ftplib module now defaults to passive mode, which is deemed a
2216 more useful default given that clients are often inside firewalls
2217 these days. Note that this could break if ftplib is used to connect
2218 to a *server* that is inside a firewall, from outside; this is
2219 expected to be a very rare situation. To fix that, you can call
2220 ftp.set_pasv(0).
2221
Martin v. Löwis10a27872001-01-13 09:54:41 +00002222- The module site now treats .pth files not only for path configuration,
2223 but also supports extensions to the initialization code: Lines starting
2224 with import are executed.
2225
Guido van Rossumf61f1662001-01-10 20:13:55 +00002226- There's a new module, warnings, which implements a mechanism for
2227 issuing and filtering warnings. There are some new built-in
2228 exceptions that serve as warning categories, and a new command line
2229 option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
2230 turns warnings into errors). warnings.warn(message[, category])
2231 issues a warning message; this can also be called from C as
2232 PyErr_Warn(category, message).
2233
2234- A new module xreadlines was added. This exports a single factory
2235 function, xreadlines(). The intention is that this code is the
2236 absolutely fastest way to iterate over all lines in an open
2237 file(-like) object:
2238
2239 import xreadlines
2240 for line in xreadlines.xreadlines(file):
2241 ...do something to line...
2242
2243 This is equivalent to the previous the speed record holder using
2244 file.readlines(sizehint). Note that if file is a real file object
2245 (as opposed to a file-like object), this is equivalent:
2246
2247 for line in file.xreadlines():
2248 ...do something to line...
2249
Tim Peters36cdad12000-12-29 02:06:45 +00002250- The bisect module has new functions bisect_left, insort_left,
2251 bisect_right and insort_right. The old names bisect and insort
2252 are now aliases for bisect_right and insort_right. XXX_right
2253 and XXX_left methods differ in what happens when the new element
2254 compares equal to one or more elements already in the list: the
2255 XXX_left methods insert to the left, the XXX_right methods to the
Tim Peters742bb6f2001-01-05 08:05:32 +00002256 right. Code that doesn't care where equal elements end up should
2257 continue to use the old, short names ("bisect" and "insort").
Tim Peters36cdad12000-12-29 02:06:45 +00002258
Andrew M. Kuchlingf6f3a892001-01-13 14:53:34 +00002259- The new curses.panel module wraps the panel library that forms part
2260 of SYSV curses and ncurses. Contributed by Thomas Gellekum.
2261
Guido van Rossumf61f1662001-01-10 20:13:55 +00002262- The SocketServer module now sets the allow_reuse_address flag by
2263 default in the TCPServer class.
2264
2265- A new function, sys._getframe(), returns the stack frame pointer of
2266 the caller. This is intended only as a building block for
2267 higher-level mechanisms such as string interpolation.
2268
Martin v. Löwis2a5130e2001-02-27 04:21:58 +00002269- The pyexpat module supports a number of new handlers, which are
2270 available only in expat 1.2. If invocation of a callback fails, it
2271 will report an additional frame in the traceback. Parser objects
2272 participate now in garbage collection. If expat reports an unknown
2273 encoding, pyexpat will try to use a Python codec; that works only
2274 for single-byte charsets. The parser type objects is exposed as
2275 XMLParserObject.
2276
2277- xml.dom now offers standard definitions for symbolic node type and
2278 exception code constants, and a hierarchy of DOM exceptions. minidom
2279 was adjusted to use them.
2280
2281- The conformance of xml.dom.minidom to the DOM specification was
2282 improved. It detects a number of additional error cases; the
2283 previous/next relationship works even when the tree is modified;
2284 Node supports the normalize() method; NamedNodeMap, DocumentType and
2285 DOMImplementation classes were added; Element supports the
2286 hasAttribute and hasAttributeNS methods; and Text supports the splitText
2287 method.
2288
Guido van Rossumf61f1662001-01-10 20:13:55 +00002289Build issues
2290
Guido van Rossum1e33bdc2001-01-23 03:17:00 +00002291- For Unix (and Unix-compatible) builds, configuration and building of
2292 extension modules is now greatly automated. Rather than having to
2293 edit the Modules/Setup file to indicate which modules should be
2294 built and where their include files and libraries are, a
2295 distutils-based setup.py script now takes care of building most
2296 extension modules. All extension modules built this way are built
2297 as shared libraries. Only a few modules that must be linked
2298 statically are still listed in the Setup file; you won't need to
2299 edit their configuration.
2300
2301- Python should now build out of the box on Cygwin. If it doesn't,
2302 mail to Jason Tishler (jlt63 at users.sourceforge.net).
Guido van Rossumf61f1662001-01-10 20:13:55 +00002303
2304- Python now always uses its own (renamed) implementation of getopt()
2305 -- there's too much variation among C library getopt()
2306 implementations.
2307
2308- C++ compilers are better supported; the CXX macro is always set to a
2309 C++ compiler if one is found.
Tim Peters36cdad12000-12-29 02:06:45 +00002310
Tim Petersd92dfe02000-12-12 01:18:41 +00002311Windows changes
2312
2313- select module: By default under Windows, a select() call
2314 can specify no more than 64 sockets. Python now boosts
2315 this Microsoft default to 512. If you need even more than
2316 that, see the MS docs (you'll need to #define FD_SETSIZE
2317 and recompile Python from source).
2318
Guido van Rossumf61f1662001-01-10 20:13:55 +00002319- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
2320 subdirectory is no more!
2321
Tim Petersa3a3a032000-11-30 05:22:44 +00002322
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002323What's New in Python 2.0?
Fred Drake1a640502000-10-16 20:27:25 +00002324=========================
Guido van Rossum61000331997-08-15 04:39:58 +00002325
Guido van Rossum8ed602b2000-09-01 22:34:33 +00002326Below is a list of all relevant changes since release 1.6. Older
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002327changes are in the file HISTORY. If you are making the jump directly
2328from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
2329HISTORY file! Many important changes listed there.
Guido van Rossum61000331997-08-15 04:39:58 +00002330
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002331Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
2332the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
2333http://starship.python.net/crew/amk/python/writing/new-python/.
Guido van Rossum1f83cce1997-10-06 21:04:35 +00002334
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002335--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
Guido van Rossum437cfe81999-04-08 20:17:57 +00002336
2337======================================================================
2338
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002339What's new in 2.0 (since release candidate 1)?
2340==============================================
2341
2342Standard library
2343
2344- The copy_reg module was modified to clarify its intended use: to
2345 register pickle support for extension types, not for classes.
2346 pickle() will raise a TypeError if it is passed a class.
2347
2348- Fixed a bug in gettext's "normalize and expand" code that prevented
2349 it from finding an existing .mo file.
2350
2351- Restored support for HTTP/0.9 servers in httplib.
2352
Tim Peters989b7b92000-10-16 20:24:53 +00002353- The math module was changed to stop raising OverflowError in case of
2354 underflow, and return 0 instead in underflow cases. Whether Python
2355 used to raise OverflowError in case of underflow was platform-
2356 dependent (it did when the platform math library set errno to ERANGE
2357 on underflow).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002358
2359- Fixed a bug in StringIO that occurred when the file position was not
2360 at the end of the file and write() was called with enough data to
2361 extend past the end of the file.
2362
2363- Fixed a bug that caused Tkinter error messages to get lost on
2364 Windows. The bug was fixed by replacing direct use of
2365 interp->result with Tcl_GetStringResult(interp).
2366
2367- Fixed bug in urllib2 that caused it to fail when it received an HTTP
2368 redirect response.
2369
2370- Several changes were made to distutils: Some debugging code was
2371 removed from util. Fixed the installer used when an external zip
2372 program (like WinZip) is not found; the source code for this
2373 installer is in Misc/distutils. check_lib() was modified to behave
2374 more like AC_CHECK_LIB by add other_libraries() as a parameter. The
2375 test for whether installed modules are on sys.path was changed to
2376 use both normcase() and normpath().
2377
Jeremy Hyltond867a2c2000-10-16 20:41:38 +00002378- Several minor bugs were fixed in the xml package (the minidom,
2379 pulldom, expatreader, and saxutils modules).
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002380
2381- The regression test driver (regrtest.py) behavior when invoked with
2382 -l changed: It now reports a count of objects that are recognized as
2383 garbage but not freed by the garbage collector.
2384
Tim Peters989b7b92000-10-16 20:24:53 +00002385- The regression test for the math module was changed to test
2386 exceptional behavior when the test is run in verbose mode. Python
2387 cannot yet guarantee consistent exception behavior across platforms,
2388 so the exception part of test_math is run only in verbose mode, and
2389 may fail on your platform.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002390
2391Internals
2392
2393- PyOS_CheckStack() has been disabled on Win64, where it caused
2394 test_sre to fail.
2395
2396Build issues
2397
2398- Changed compiler flags, so that gcc is always invoked with -Wall and
2399 -Wstrict-prototypes. Users compiling Python with GCC should see
2400 exactly one warning, except if they have passed configure the
Tim Peters989b7b92000-10-16 20:24:53 +00002401 --with-pydebug flag. The expected warning is for getopt() in
Tim Petersadfb94f2000-10-16 20:51:33 +00002402 Modules/main.c. This warning will be fixed for Python 2.1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002403
Tim Petersa3a3a032000-11-30 05:22:44 +00002404- Fixed configure to add -threads argument during linking on OSF1.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002405
2406Tools and other miscellany
2407
2408- The compiler in Tools/compiler was updated to support the new
2409 language features introduced in 2.0: extended print statement, list
2410 comprehensions, and augmented assignments. The new compiler should
2411 also be backwards compatible with Python 1.5.2; the compiler will
2412 always generate code for the version of the interpreter it runs
Tim Petersa3a3a032000-11-30 05:22:44 +00002413 under.
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002414
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002415What's new in 2.0 release candidate 1 (since beta 2)?
2416=====================================================
2417
Jeremy Hylton6040aaa2000-10-09 21:27:22 +00002418What is release candidate 1?
2419
2420We believe that release candidate 1 will fix all known bugs that we
2421intend to fix for the 2.0 final release. This release should be a bit
2422more stable than the previous betas. We would like to see even more
2423widespread testing before the final release, so we are producing this
2424release candidate. The final release will be exactly the same unless
2425any show-stopping (or brown bag) bugs are found by testers of the
2426release candidate.
2427
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002428All the changes since the last beta release are bug fixes or changes
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002429to support building Python for specific platforms.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002430
2431Core language, builtins, and interpreter
2432
2433- A bug that caused crashes when __coerce__ was used with augmented
2434 assignment, e.g. +=, was fixed.
2435
2436- Raise ZeroDivisionError when raising zero to a negative number,
2437 e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
2438 power operator and the result of math.pow(0.0, -2.0) will vary by
2439 platform. On Linux, it raises a ValueError.
2440
2441- A bug in Unicode string interpolation was fixed that occasionally
2442 caused errors with formats including "%%". For example, the
2443 following expression "%% %s" % u"abc" no longer raises a TypeError.
2444
2445- Compilation of deeply nested expressions raises MemoryError instead
2446 of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
2447
2448- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
2449 rendering them useless. They are now written in binary mode again.
2450
2451Standard library
2452
2453- Keyword arguments are now accepted for most pattern and match object
2454 methods in SRE, the standard regular expression engine.
2455
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002456- In SRE, fixed error with negative lookahead and lookbehind that
Jeremy Hylton32e20ff2000-10-09 19:48:11 +00002457 manifested itself as a runtime error in patterns like "(?<!abc)(def)".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002458
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002459- Several bugs in the Unicode handling and error handling in _tkinter
2460 were fixed.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002461
2462- Fix memory management errors in Merge() and Tkapp_Call() routines.
2463
2464- Several changes were made to cStringIO to make it compatible with
2465 the file-like object interface and with StringIO. If operations are
2466 performed on a closed object, an exception is raised. The truncate
2467 method now accepts a position argument and readline accepts a size
Tim Petersa3a3a032000-11-30 05:22:44 +00002468 argument.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002469
2470- There were many changes made to the linuxaudiodev module and its
2471 test suite; as a result, a short, unexpected audio sample should now
Tim Petersa3a3a032000-11-30 05:22:44 +00002472 play when the regression test is run.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002473
2474 Note that this module is named poorly, because it should work
2475 correctly on any platform that supports the Open Sound System
Tim Petersa3a3a032000-11-30 05:22:44 +00002476 (OSS).
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002477
2478 The module now raises exceptions when errors occur instead of
2479 crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
2480 audio) and defines a getptr() method that calls the
2481 SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
2482
2483- The library_version attribute, introduced in an earlier beta, was
2484 removed because it can not be supported with early versions of the C
2485 readline library, which provides no way to determine the version at
2486 compile-time.
2487
2488- The binascii module is now enabled on Win64.
2489
Tim Peters46446d62000-10-09 21:19:31 +00002490- tokenize.py no longer suffers "recursion depth" errors when parsing
2491 programs with very long string literals.
2492
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002493Internals
2494
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002495- Fixed several buffer overflow vulnerabilities in calculate_path(),
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002496 which is called when the interpreter starts up to determine where
2497 the standard library is installed. These vulnerabilities affect all
2498 previous versions of Python and can be exploited by setting very
2499 long values for PYTHONHOME or argv[0]. The risk is greatest for a
2500 setuid Python script, although use of the wrapper in
2501 Misc/setuid-prog.c will eliminate the vulnerability.
2502
2503- Fixed garbage collection bugs in instance creation that were
2504 triggered when errors occurred during initialization. The solution,
2505 applied in cPickle and in PyInstance_New(), is to call
2506 PyObject_GC_Init() after the initialization of the object's
2507 container attributes is complete.
2508
2509- pyexpat adds definitions of PyModule_AddStringConstant and
2510 PyModule_AddObject if the Python version is less than 2.0, which
2511 provides compatibility with PyXML on Python 1.5.2.
2512
2513- If the platform has a bogus definition for LONG_BIT (the number of
2514 bits in a long), an error will be reported at compile time.
2515
2516- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
2517 collection crashes and possibly other, unreported crashes.
2518
2519- Fixed a memory leak in _PyUnicode_Fini().
2520
2521Build issues
2522
2523- configure now accepts a --with-suffix option that specifies the
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002524 executable suffix. This is useful for builds on Cygwin and Mac OS
Tim Petersa3a3a032000-11-30 05:22:44 +00002525 X, for example.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002526
2527- The mmap.PAGESIZE constant is now initialized using sysconf when
2528 possible, which eliminates a dependency on -lucb for Reliant UNIX.
2529
2530- The md5 file should now compile on all platforms.
2531
2532- The select module now compiles on platforms that do not define
2533 POLLRDNORM and related constants.
2534
2535- Darwin (Mac OS X): Initial support for static builds on this
Tim Petersa3a3a032000-11-30 05:22:44 +00002536 platform.
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002537
Jeremy Hylton10921202000-10-09 18:34:12 +00002538- BeOS: A number of changes were made to the build and installation
2539 process. ar-fake now operates on a directory of object files.
2540 dl_export.h is gone, and its macros now appear on the mwcc command
2541 line during build on PPC BeOS.
2542
Jeremy Hyltond6e20232000-10-16 20:08:38 +00002543- Platform directory in lib/python2.0 is "plat-beos5" (or
Jeremy Hylton10921202000-10-09 18:34:12 +00002544 "plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
Jeremy Hyltoned9e6442000-10-09 18:26:42 +00002545
2546- Cygwin: Support for shared libraries, Tkinter, and sockets.
2547
2548- SunOS 4.1.4_JL: Fix test for directory existence in configure.
2549
2550Tools and other miscellany
2551
2552- Removed debugging prints from main used with freeze.
2553
Tim Peters46446d62000-10-09 21:19:31 +00002554- IDLE auto-indent no longer crashes when it encounters Unicode
2555 characters.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002556
2557What's new in 2.0 beta 2 (since beta 1)?
2558========================================
2559
2560Core language, builtins, and interpreter
2561
Tim Peters482c0212000-09-26 06:33:09 +00002562- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002563 "%d" % 2L**64 == "18446744073709551616".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002564
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002565- Add -h and -V command line options to print the usage message and
2566 Python version number and exit immediately.
2567
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002568- eval() and exec accept Unicode objects as code parameters.
2569
2570- getattr() and setattr() now also accept Unicode objects for the
2571 attribute name, which are converted to strings using the default
2572 encoding before lookup.
2573
2574- Multiplication on string and Unicode now does proper bounds
2575 checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
2576 string is too long."
2577
2578- Better error message when continue is found in try statement in a
Tim Petersa3a3a032000-11-30 05:22:44 +00002579 loop.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002580
Jeremy Hylton1b618592000-09-26 05:32:36 +00002581
2582Standard library and extensions
2583
Guido van Rossum5b08f132001-04-16 02:05:23 +00002584- socket module: the OpenSSL code now adds support for RAND_status()
2585 and EGD (Entropy Gathering Device).
2586
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002587- array: reverse() method of array now works. buffer_info() now does
Jeremy Hylton1b618592000-09-26 05:32:36 +00002588 argument checking; it still takes no arguments.
2589
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002590- asyncore/asynchat: Included most recent version from Sam Rushing.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002591
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002592- cgi: Accept '&' or ';' as separator characters when parsing form data.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002593
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002594- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002595
2596- ConfigParser: When reading the file, options spelled in upper case
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002597 letters are now correctly converted to lowercase.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002598
2599- copy: Copy Unicode objects atomically.
2600
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002601- cPickle: Fail gracefully when copy_reg can't be imported.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002602
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002603- cStringIO: Implemented readlines() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002604
Fred Drake67233bc2000-09-26 16:40:27 +00002605- dbm: Add get() and setdefault() methods to dbm object. Add constant
2606 `library' to module that names the library used. Added doc strings
2607 and method names to error messages. Uses configure to determine
2608 which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
2609 now available options.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002610
2611- distutils: Update to version 0.9.3.
2612
2613- dl: Add several dl.RTLD_ constants.
2614
2615- fpectl: Now supported on FreeBSD.
2616
2617- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
2618 found by the collector will be saved in gc.garbage. This is useful
2619 for debugging a program that creates reference cycles.
2620
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002621- httplib: Three changes: Restore support for set_debuglevel feature
Jeremy Hylton1b618592000-09-26 05:32:36 +00002622 of HTTP class. Do not close socket on zero-length response. Do not
2623 crash when server sends invalid content-length header.
2624
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002625- mailbox: Mailbox class conforms better to qmail specifications.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002626
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002627- marshal: When reading a short, sign-extend on platforms where shorts
2628 are bigger than 16 bits. When reading a long, repair the unportable
2629 sign extension that was being done for 64-bit machines. (It assumed
2630 that signed right shift sign-extends.)
2631
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002632- operator: Add contains(), invert(), __invert__() as aliases for
2633 __contains__(), inv(), and __inv__() respectively.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002634
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002635- os: Add support for popen2() and popen3() on all platforms where
2636 fork() exists. (popen4() is still in the works.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002637
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002638- os: (Windows only:) Add startfile() function that acts like double-
Tim Peters482c0212000-09-26 06:33:09 +00002639 clicking on a file in Explorer (or passing the file name to the
2640 DOS "start" command).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002641
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002642- os.path: (Windows, DOS:) Treat trailing colon correctly in
Tim Peters482c0212000-09-26 06:33:09 +00002643 os.path.join. os.path.join("a:", "b") yields "a:b".
Jeremy Hylton1b618592000-09-26 05:32:36 +00002644
2645- pickle: Now raises ValueError when an invalid pickle that contains
2646 a non-string repr where a string repr was expected. This behavior
2647 matches cPickle.
2648
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002649- posixfile: Remove broken __del__() method.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002650
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002651- py_compile: support CR+LF line terminators in source file.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002652
2653- readline: Does not immediately exit when ^C is hit when readline and
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002654 threads are configured. Adds definition of rl_library_version. (The
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002655 latter addition requires GNU readline 2.2 or later.)
Jeremy Hylton1b618592000-09-26 05:32:36 +00002656
2657- rfc822: Domain literals returned by AddrlistClass method
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002658 getdomainliteral() are now properly wrapped in brackets.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002659
2660- site: sys.setdefaultencoding() should only be called in case the
Tim Peters482c0212000-09-26 06:33:09 +00002661 standard default encoding ("ascii") is changed. This saves quite a
Jeremy Hylton1b618592000-09-26 05:32:36 +00002662 few cycles during startup since the first call to
2663 setdefaultencoding() will initialize the codec registry and the
2664 encodings package.
2665
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002666- socket: Support for size hint in readlines() method of object returned
2667 by makefile().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002668
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002669- sre: Added experimental expand() method to match objects. Does not
Jeremy Hylton625915e2000-10-02 13:43:33 +00002670 use buffer interface on Unicode strings. Does not hang if group id
Jeremy Hylton1b618592000-09-26 05:32:36 +00002671 is followed by whitespace.
2672
Tim Petersa3a3a032000-11-30 05:22:44 +00002673- StringIO: Size hint in readlines() is now supported as documented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002674
2675- struct: Check ranges for bytes and shorts.
2676
2677- urllib: Improved handling of win32 proxy settings. Fixed quote and
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002678 quote_plus functions so that the always encode a comma.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002679
2680- Tkinter: Image objects are now guaranteed to have unique ids. Set
2681 event.delta to zero if Tk version doesn't support mousewheel.
2682 Removed some debugging prints.
2683
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002684- UserList: now implements __contains__().
Jeremy Hylton1b618592000-09-26 05:32:36 +00002685
Fred Drake67233bc2000-09-26 16:40:27 +00002686- webbrowser: On Windows, use os.startfile() instead of os.popen(),
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002687 which works around a bug in Norton AntiVirus 2000 that leads directly
2688 to a Blue Screen freeze.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002689
2690- xml: New version detection code allows PyXML to override standard
2691 XML package if PyXML version is greater than 0.6.1.
2692
Fred Drake64bb3802000-09-26 16:21:35 +00002693- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
2694 (conventional DOM), and xml.dom.pulldom, which allows building the DOM
2695 tree only for nodes which are sufficiently interesting to a specific
2696 application. Does not provide the HTML-specific extensions. Still
2697 undocumented.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002698
Fred Drake64bb3802000-09-26 16:21:35 +00002699- xml.sax: SAX 2 support for Python, including all the handler
2700 interfaces needed to process XML 1.0 compliant XML. Some
2701 documentation is already available.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002702
Fred Drake64bb3802000-09-26 16:21:35 +00002703- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
2704 packagized XML support.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002705
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002706
Jeremy Hylton1b618592000-09-26 05:32:36 +00002707C API
2708
2709- Add three new convenience functions for module initialization --
2710 PyModule_AddObject(), PyModule_AddIntConstant(), and
2711 PyModule_AddStringConstant().
2712
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002713- Cleaned up definition of NULL in C source code; all definitions were
Jeremy Hylton1b618592000-09-26 05:32:36 +00002714 removed and add #error to Python.h if NULL isn't defined after
2715 #include of stdio.h.
2716
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002717- Py_PROTO() macros that were removed in 2.0b1 have been restored for
Jeremy Hylton1b618592000-09-26 05:32:36 +00002718 backwards compatibility (at the source level) with old extensions.
2719
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002720- A wrapper API was added for signal() and sigaction(). Instead of
2721 either function, always use PyOS_getsig() to get a signal handler
2722 and PyOS_setsig() to set one. A new convenience typedef
2723 PyOS_sighandler_t is defined for the type of signal handlers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002724
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002725- Add PyString_AsStringAndSize() function that provides access to the
Jeremy Hylton1b618592000-09-26 05:32:36 +00002726 internal data buffer and size of a string object -- or the default
2727 encoded version of a Unicode object.
2728
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002729- PyString_Size() and PyString_AsString() accept Unicode objects.
2730
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002731- The standard header <limits.h> is now included by Python.h (if it
Fred Drake64bb3802000-09-26 16:21:35 +00002732 exists). INT_MAX and LONG_MAX will always be defined, even if
2733 <limits.h> is not available.
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002734
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002735- PyFloat_FromString takes a second argument, pend, that was
2736 effectively useless. It is now officially useless but preserved for
2737 backwards compatibility. If the pend argument is not NULL, *pend is
2738 set to NULL.
2739
2740- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
2741 for the attribute name. See note on getattr() above.
2742
2743- A few bug fixes to argument processing for Unicode.
2744 PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
2745 PyArg_Parse() special cases "s#" for Unicode objects; it returns a
2746 pointer to the default encoded string data instead of to the raw
Tim Petersa3a3a032000-11-30 05:22:44 +00002747 UTF-16.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002748
2749- Py_BuildValue accepts B format (for bgen-generated code).
2750
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002751
Jeremy Hylton1b618592000-09-26 05:32:36 +00002752Internals
2753
2754- On Unix, fix code for finding Python installation directory so that
2755 it works when argv[0] is a relative path.
2756
Andrew M. Kuchlinga1099be2000-12-15 01:16:43 +00002757- Added a true unicode_internal_encode() function and fixed the
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002758 unicode_internal_decode function() to support Unicode objects directly
Jeremy Hylton1b618592000-09-26 05:32:36 +00002759 rather than by generating a copy of the object.
2760
Tim Peters482c0212000-09-26 06:33:09 +00002761- Several of the internal Unicode tables are much smaller now, and
2762 the source code should be much friendlier to weaker compilers.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002763
Jeremy Hylton97693b02000-09-26 17:42:51 +00002764- In the garbage collector: Fixed bug in collection of tuples. Fixed
2765 bug that caused some instances to be removed from the container set
2766 while they were still live. Fixed parsing in gc.set_debug() for
2767 platforms where sizeof(long) > sizeof(int).
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002768
2769- Fixed refcount problem in instance deallocation that only occurred
2770 when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
2771
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002772- On Windows, getpythonregpath is now protected against null data in
2773 registry key.
2774
2775- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
Tim Petersa3a3a032000-11-30 05:22:44 +00002776 condition.
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002777
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002778
Jeremy Hylton1b618592000-09-26 05:32:36 +00002779Build and platform-specific issues
2780
2781- Better support of GNU Pth via --with-pth configure option.
2782
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002783- Python/C API now properly exposed to dynamically-loaded extension
2784 modules on Reliant UNIX.
Jeremy Hylton1b618592000-09-26 05:32:36 +00002785
2786- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
2787 Don't define MS_SYNC to be zero when it is undefined. Added missing
2788 prototypes in posixmodule.c.
2789
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002790- Improved support for HP-UX build. Threads should now be correctly
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002791 configured (on HP-UX 10.20 and 11.00).
Jeremy Hylton1b618592000-09-26 05:32:36 +00002792
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002793- Fix largefile support on older NetBSD systems and OpenBSD by adding
2794 define for TELL64.
2795
2796
2797Tools and other miscellany
2798
2799- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
2800
2801- freeze: The modulefinder now works with 2.0 opcodes.
2802
Tim Petersa3a3a032000-11-30 05:22:44 +00002803- IDLE:
Jeremy Hyltonfa2e2c12000-09-26 16:31:30 +00002804 Move hackery of sys.argv until after the Tk instance has been
2805 created, which allows the application-specific Tkinter
2806 initialization to be executed if present; also pass an explicit
2807 className parameter to the Tk() constructor.
Fred Drake64bb3802000-09-26 16:21:35 +00002808
Jeremy Hylton1b618592000-09-26 05:32:36 +00002809
2810What's new in 2.0 beta 1?
2811=========================
2812
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002813Source Incompatibilities
2814------------------------
2815
2816None. Note that 1.6 introduced several incompatibilities with 1.5.2,
2817such as single-argument append(), connect() and bind(), and changes to
2818str(long) and repr(float).
2819
2820
2821Binary Incompatibilities
2822------------------------
2823
2824- Third party extensions built for Python 1.5.x or 1.6 cannot be used
2825with Python 2.0; these extensions will have to be rebuilt for Python
28262.0.
2827
2828- On Windows, attempting to import a third party extension built for
2829Python 1.5.x or 1.6 results in an immediate crash; there's not much we
2830can do about this. Check your PYTHONPATH environment variable!
2831
2832- Python bytecode files (*.pyc and *.pyo) are not compatible between
2833releases.
2834
2835
2836Overview of Changes Since 1.6
2837-----------------------------
2838
2839There are many new modules (including brand new XML support through
2840the xml package, and i18n support through the gettext module); a list
2841of all new modules is included below. Lots of bugs have been fixed.
2842
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002843The process for making major new changes to the language has changed
2844since Python 1.6. Enhancements must now be documented by a Python
2845Enhancement Proposal (PEP) before they can be accepted.
2846
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002847There are several important syntax enhancements, described in more
2848detail below:
2849
2850 - Augmented assignment, e.g. x += 1
2851
2852 - List comprehensions, e.g. [x**2 for x in range(10)]
2853
2854 - Extended import statement, e.g. import Module as Name
2855
2856 - Extended print statement, e.g. print >> file, "Hello"
2857
2858Other important changes:
2859
2860 - Optional collection of cyclical garbage
2861
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002862Python Enhancement Proposal (PEP)
2863---------------------------------
2864
2865PEP stands for Python Enhancement Proposal. A PEP is a design
2866document providing information to the Python community, or describing
2867a new feature for Python. The PEP should provide a concise technical
2868specification of the feature and a rationale for the feature.
2869
2870We intend PEPs to be the primary mechanisms for proposing new
2871features, for collecting community input on an issue, and for
2872documenting the design decisions that have gone into Python. The PEP
2873author is responsible for building consensus within the community and
2874documenting dissenting opinions.
2875
2876The PEPs are available at http://python.sourceforge.net/peps/.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002877
2878Augmented Assignment
2879--------------------
2880
2881This must have been the most-requested feature of the past years!
2882Eleven new assignment operators were added:
2883
Guido van Rossume905e952000-09-05 12:42:46 +00002884 += -= *= /= %= **= <<= >>= &= ^= |=
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002885
2886For example,
2887
2888 A += B
2889
2890is similar to
2891
2892 A = A + B
2893
2894except that A is evaluated only once (relevant when A is something
2895like dict[index].attr).
2896
2897However, if A is a mutable object, A may be modified in place. Thus,
2898if A is a number or a string, A += B has the same effect as A = A+B
2899(except A is only evaluated once); but if a is a list, A += B has the
2900same effect as A.extend(B)!
2901
2902Classes and built-in object types can override the new operators in
2903order to implement the in-place behavior; the not-in-place behavior is
2904used automatically as a fallback when an object doesn't implement the
2905in-place behavior. For classes, the method name is derived from the
2906method name for the corresponding not-in-place operator by inserting
2907an 'i' in front of the name, e.g. __iadd__ implements in-place
2908__add__.
2909
2910Augmented assignment was implemented by Thomas Wouters.
2911
2912
2913List Comprehensions
2914-------------------
2915
2916This is a flexible new notation for lists whose elements are computed
2917from another list (or lists). The simplest form is:
2918
2919 [<expression> for <variable> in <sequence>]
2920
Guido van Rossum56db0952000-09-06 23:34:25 +00002921For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002922This is more efficient than a for loop with a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002923
2924You can also add a condition:
2925
2926 [<expression> for <variable> in <sequence> if <condition>]
2927
2928For example, [w for w in words if w == w.lower()] would yield the list
2929of words that contain no uppercase characters. This is more efficient
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00002930than a for loop with an if statement and a list.append() call.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002931
2932You can also have nested for loops and more than one 'if' clause. For
2933example, here's a function that flattens a sequence of sequences::
2934
2935 def flatten(seq):
2936 return [x for subseq in seq for x in subseq]
2937
2938 flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
2939
2940This prints
2941
2942 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
2943
2944List comprehensions originated as a patch set from Greg Ewing; Skip
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002945Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002946
2947
2948Extended Import Statement
2949-------------------------
2950
2951Many people have asked for a way to import a module under a different
2952name. This can be accomplished like this:
2953
2954 import foo
2955 bar = foo
2956 del foo
2957
2958but this common idiom gets old quickly. A simple extension of the
2959import statement now allows this to be written as follows:
2960
2961 import foo as bar
2962
2963There's also a variant for 'from ... import':
2964
2965 from foo import bar as spam
2966
2967This also works with packages; e.g. you can write this:
2968
2969 import test.regrtest as regrtest
2970
2971Note that 'as' is not a new keyword -- it is recognized only in this
2972context (this is only possible because the syntax for the import
2973statement doesn't involve expressions).
2974
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002975Implemented by Thomas Wouters. Described by PEP 221.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002976
2977
2978Extended Print Statement
2979------------------------
2980
2981Easily the most controversial new feature, this extension to the print
2982statement adds an option to make the output go to a different file
2983than the default sys.stdout.
2984
2985For example, to write an error message to sys.stderr, you can now
2986write:
2987
2988 print >> sys.stderr, "Error: bad dog!"
2989
2990As a special feature, if the expression used to indicate the file
Fred Drake45888ff2000-09-29 17:09:11 +00002991evaluates to None, the current value of sys.stdout is used. Thus:
Guido van Rossumf2ffce02000-09-05 04:38:34 +00002992
2993 print >> None, "Hello world"
2994
2995is equivalent to
2996
2997 print "Hello world"
2998
Jeremy Hylton24c3d602000-09-05 19:36:26 +00002999Design and implementation by Barry Warsaw. Described by PEP 214.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003000
3001
3002Optional Collection of Cyclical Garbage
3003---------------------------------------
3004
3005Python is now equipped with a garbage collector that can hunt down
3006cyclical references between Python objects. It's no replacement for
3007reference counting; in fact, it depends on the reference counts being
3008correct, and decides that a set of objects belong to a cycle if all
3009their reference counts can be accounted for from their references to
3010each other. This devious scheme was first proposed by Eric Tiedemann,
3011and brought to implementation by Neil Schemenauer.
3012
3013There's a module "gc" that lets you control some parameters of the
3014garbage collection. There's also an option to the configure script
3015that lets you enable or disable the garbage collection. In 2.0b1,
3016it's on by default, so that we (hopefully) can collect decent user
3017experience with this new feature. There are some questions about its
Fred Drake9f11cf82000-09-29 17:54:40 +00003018performance. If it proves to be too much of a problem, we'll turn it
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003019off by default in the final 2.0 release.
3020
3021
3022Smaller Changes
3023---------------
3024
3025A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
3026map(None, seq1, seq2, ...) when the sequences have the same length;
3027i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
3028the lists are not all the same length, the shortest list wins:
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003029zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003030
3031sys.version_info is a tuple (major, minor, micro, level, serial).
3032
3033Dictionaries have an odd new method, setdefault(key, default).
3034dict.setdefault(key, default) returns dict[key] if it exists; if not,
3035it sets dict[key] to default and returns that value. Thus:
3036
3037 dict.setdefault(key, []).append(item)
3038
3039does the same work as this common idiom:
3040
3041 if not dict.has_key(key):
3042 dict[key] = []
3043 dict[key].append(item)
3044
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003045There are two new variants of SyntaxError that are raised for
3046indentation-related errors: IndentationError and TabError.
3047
3048Changed \x to consume exactly two hex digits; see PEP 223. Added \U
3049escape that consumes exactly eight hex digits.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003050
3051The limits on the size of expressions and file in Python source code
3052have been raised from 2**16 to 2**32. Previous versions of Python
3053were limited because the maximum argument size the Python VM accepted
3054was 2**16. This limited the size of object constructor expressions,
3055e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
3056limit was raised thanks to a patch by Charles Waldman that effectively
3057fixes the problem. It is now much more likely that you will be
3058limited by available memory than by an arbitrary limit in Python.
3059
3060The interpreter's maximum recursion depth can be modified by Python
3061programs using sys.getrecursionlimit and sys.setrecursionlimit. This
3062limit is the maximum number of recursive calls that can be made by
3063Python code. The limit exists to prevent infinite recursion from
3064overflowing the C stack and causing a core dump. The default value is
30651000. The maximum safe value for a particular platform can be found
3066by running Misc/find_recursionlimit.py.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003067
3068New Modules and Packages
3069------------------------
3070
3071atexit - for registering functions to be called when Python exits.
3072
3073imputil - Greg Stein's alternative API for writing custom import
3074hooks.
3075
3076pyexpat - an interface to the Expat XML parser, contributed by Paul
3077Prescod.
3078
3079xml - a new package with XML support code organized (so far) in three
3080subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
3081would fill a volume. There's a special feature whereby a
3082user-installed package named _xmlplus overrides the standard
3083xmlpackage; this is intended to give the XML SIG a hook to distribute
3084backwards-compatible updates to the standard xml package.
3085
3086webbrowser - a platform-independent API to launch a web browser.
3087
3088
Guido van Rossume905e952000-09-05 12:42:46 +00003089Changed Modules
3090---------------
3091
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003092array -- new methods for array objects: count, extend, index, pop, and
3093remove
3094
3095binascii -- new functions b2a_hex and a2b_hex that convert between
3096binary data and its hex representation
3097
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003098calendar -- Many new functions that support features including control
3099over which day of the week is the first day, returning strings instead
3100of printing them. Also new symbolic constants for days of week,
3101e.g. MONDAY, ..., SUNDAY.
3102
3103cgi -- FieldStorage objects have a getvalue method that works like a
3104dictionary's get method and returns the value attribute of the object.
3105
3106ConfigParser -- The parser object has new methods has_option,
3107remove_section, remove_option, set, and write. They allow the module
3108to be used for writing config files as well as reading them.
3109
3110ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
Guido van Rossume905e952000-09-05 12:42:46 +00003111optionally support the RFC 959 REST command.
3112
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003113gzip -- readline and readlines now accept optional size arguments
Guido van Rossume905e952000-09-05 12:42:46 +00003114
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003115httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
3116the module doc strings for details.
Guido van Rossum830ca2a2000-09-05 15:34:16 +00003117
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003118locale -- implement getdefaultlocale for Win32 and Macintosh
3119
3120marshal -- no longer dumps core when marshaling deeply nested or
3121recursive data structures
3122
3123os -- new functions isatty, seteuid, setegid, setreuid, setregid
3124
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003125os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
3126support under Unix.
3127
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003128os/pty -- support for openpty and forkpty
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003129
3130os.path -- fix semantics of os.path.commonprefix
3131
3132smtplib -- support for sending very long messages
3133
3134socket -- new function getfqdn()
3135
3136readline -- new functions to read, write and truncate history files.
3137The readline section of the library reference manual contains an
3138example.
3139
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003140select -- add interface to poll system call
3141
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003142shutil -- new copyfileobj function
3143
3144SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
3145HTTP server.
3146
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003147Tkinter -- optimization of function flatten
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003148
3149urllib -- scans environment variables for proxy configuration,
Tim Peters8b092332000-09-05 20:15:25 +00003150e.g. http_proxy.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003151
3152whichdb -- recognizes dumbdbm format
Guido van Rossume905e952000-09-05 12:42:46 +00003153
3154
3155Obsolete Modules
3156----------------
3157
3158None. However note that 1.6 made a whole slew of modules obsolete:
3159stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
3160poly, zmod, strop, util, whatsound.
3161
3162
3163Changed, New, Obsolete Tools
3164----------------------------
3165
Tim Peters8b092332000-09-05 20:15:25 +00003166None.
Guido van Rossume905e952000-09-05 12:42:46 +00003167
3168
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003169C-level Changes
3170---------------
3171
3172Several cleanup jobs were carried out throughout the source code.
3173
3174All C code was converted to ANSI C; we got rid of all uses of the
3175Py_PROTO() macro, which makes the header files a lot more readable.
3176
3177Most of the portability hacks were moved to a new header file,
3178pyport.h; several other new header files were added and some old
3179header files were removed, in an attempt to create a more rational set
3180of header files. (Few of these ever need to be included explicitly;
3181they are all included by Python.h.)
3182
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003183Trent Mick ensured portability to 64-bit platforms, under both Linux
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003184and Win64, especially for the new Intel Itanium processor. Mick also
3185added large file support for Linux64 and Win64.
Guido van Rossumf2ffce02000-09-05 04:38:34 +00003186
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003187The C APIs to return an object's size have been update to consistently
3188use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
3189previous versions, the abstract interfaces used PyXXX_Length and the
3190concrete interfaces used PyXXX_Size. The old names,
3191e.g. PyObject_Length, are still available for backwards compatibility
3192at the API level, but are deprecated.
3193
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003194The PyOS_CheckStack function has been implemented on Windows by
3195Fredrik Lundh. It prevents Python from failing with a stack overflow
3196on Windows.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003197
3198The GC changes resulted in creation of two new slots on object,
3199tp_traverse and tp_clear. The augmented assignment changes result in
Guido van Rossum4338a282000-09-06 13:02:08 +00003200the creation of a new slot for each in-place operator.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003201
3202The GC API creates new requirements for container types implemented in
Guido van Rossum4338a282000-09-06 13:02:08 +00003203C extension modules. See Include/objimpl.h for details.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003204
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003205PyErr_Format has been updated to automatically calculate the size of
3206the buffer needed to hold the formatted result string. This change
3207prevents crashes caused by programmer error.
Jeremy Hyltonbdebd542000-09-05 18:28:54 +00003208
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003209New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
Guido van Rossume905e952000-09-05 12:42:46 +00003210
Jeremy Hylton24c3d602000-09-05 19:36:26 +00003211PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
3212that are the same as their non-Ex counterparts except they take an
3213extra flag argument that tells them to close the file when done.
3214
3215XXX There were other API changes that should be fleshed out here.
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003216
Tim Peters8b092332000-09-05 20:15:25 +00003217
3218Windows Changes
3219---------------
3220
3221New popen2/popen3/peopen4 in os module (see Changed Modules above).
3222
3223os.popen is much more usable on Windows 95 and 98. See Microsoft
3224Knowledge Base article Q150956. The Win9x workaround described there
3225is implemented by the new w9xpopen.exe helper in the root of your
3226Python installation. Note that Python uses this internally; it is not
3227a standalone program.
3228
3229Administrator privileges are no longer required to install Python
3230on Windows NT or Windows 2000. If you have administrator privileges,
3231Python's registry info will be written under HKEY_LOCAL_MACHINE.
3232Otherwise the installer backs off to writing Python's registry info
Guido van Rossum4338a282000-09-06 13:02:08 +00003233under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
Tim Peters8b092332000-09-05 20:15:25 +00003234uses of Python, but will prevent some advanced uses from working
3235(for example, running a Python script as an NT service, or possibly
3236from CGI).
3237
3238[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
3239installer; instead, it installs the needed Tcl/Tk files directly in the
3240Python directory. If you already have a Tcl/Tk installation, this
3241wastes some disk space (about 4 Megs) but avoids problems with
3242conflicting Tcl/Tk installations, and makes it much easier for Python
3243to ensure that Tcl/Tk can find all its files.
3244
3245[This was new in 1.6] The Windows installer now installs by default in
3246\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
3247
Guido van Rossumf62ed9c2000-09-26 11:16:10 +00003248
3249Updates to the changes between 1.5.2 and 1.6
3250--------------------------------------------
3251
3252The 1.6 NEWS file can't be changed after the release is done, so here
3253is some late-breaking news:
3254
3255New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
3256and changes to getlocale() and setlocale().
3257
3258The new module is now enabled per default.
3259
3260It is not true that the encodings codecs cannot be used for normal
3261strings: the string.encode() (which is also present on 8-bit strings
3262!) allows using them for 8-bit strings too, e.g. to convert files from
3263cp1252 (Windows) to latin-1 or vice-versa.
3264
3265Japanese codecs are available from Tamito KAJIYAMA:
3266http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
3267
3268
Guido van Rossumab9d6f01998-08-10 22:01:13 +00003269======================================================================